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Array ( [0] => {{Short description|Kingdom of living things}} [1] => {{Other uses}} [2] => {{redirect|Animalia|other uses}} [3] => {{good article}} [4] => {{pp-semi-indef}} [5] => {{pp-move-indef}} [6] => {{Use dmy dates|date=September 2019}} [7] => {{Use British English|date=April 2017}} [8] => {{automatic taxobox [9] => | name = Animals [10] => | display_parents = 6 [11] => | taxon = Animalia [12] => | authority = [[Carl Linnaeus|Linnaeus]], [[10th edition of Systema Naturae|1758]] [13] => | fossil_range = [[Cryogenian]] – present, {{Long fossil range |665|0}} [14] => | image = [15] => File:Animal diversity b.png |300px [16] => [17] => rect 0 0 118 86 [[Echinoderm]] [18] => rect 0 86 118 172 [[Cnidaria]] [19] => rect 0 172 118 258 [[Tardigrade]] [20] => rect 0 258 118 344 [[Crustacean]] [21] => rect 0 344 118 430 [[Arachnid]] [22] => [23] => rect 118 0 236 86 [[Sponge]] [24] => rect 118 86 236 172 [[Insect]] [25] => rect 118 172 236 258 [[Bryozoa]] [26] => rect 118 258 236 344 [[Rotifer]] [27] => rect 118 344 236 430 [[Flatworm]] [28] => [29] => rect 236 0 354 86 [[Mollusca]] [30] => rect 236 86 354 172 [[Annelid]] [31] => rect 236 172 354 258 [[Vertebrate]] [32] => rect 236 258 354 344 [[Tunicate]] [33] => rect 236 344 354 430 [[Phoronida]] [34] => [35] => [36] => | image_upright = 1.4 [37] => | subdivision_ranks = Subdivisions [38] => | subdivision = *[[Bilateria]] (~30 phyla) [39] => * [[Cnidaria]] [40] => * [[Ctenophora]] [41] => * [[Placozoa]] [42] => * [[Porifera]] [43] => | synonyms = * Metazoa {{au|Haeckel 1874}}{{cite book |chapter=Metazoa E. Haeckel 1874 [J. R. Garey and K. M. Halanych], converted clade name |title=Phylonyms: A Companion to the PhyloCode |edition=1st |date=2020 |publisher=CRC Press|doi=10.1201/9780429446276 |pages=1352 |isbn=9780429446276 |s2cid=242704712 |editor-first1=Kevin |editor-last1=de Queiroz |editor-first2=Philip |editor-last2=Cantino |editor-first3=Jacques|editor-last3=Gauthier}} [44] => * Choanoblastaea {{au|Nielsen 2008}}{{cite journal |title=Six major steps in animal evolution: are we derived sponge larvae? |journal=Evolution & Development |volume=10 |issue=2 |date=2008 |pages=241–257 |first1=Claus |last1=Nielsen |doi=10.1111/j.1525-142X.2008.00231.x |pmid=18315817 |s2cid=8531859 }} [45] => * Gastrobionta {{au|Rothm. 1948}}{{cite journal |first1=Werner |last1=Rothmaler |date=1951 |title=Die Abteilungen und Klassen der Pflanzen |journal=Feddes Repertorium, Journal of Botanical Taxonomy and Geobotany |doi=10.1002/fedr.19510540208 |volume=54 |issue=2–3 |pages=256–266}} [46] => * Zooaea {{au|Barkley 1939}} [47] => * Euanimalia {{au|Barkley 1939}} [48] => }} [49] => '''Animals''' are [[multicellular]], [[eukaryotic]] [[organism]]s in the [[Kingdom (biology)|biological kingdom]] '''Animalia'''. With few exceptions, animals [[heterotroph|consume organic material]], [[Cellular respiration#Aerobic respiration|breathe oxygen]], have [[myocyte]]s and are [[motility|able to move]], can [[sexual reproduction|reproduce sexually]], and grow from a hollow sphere of cells, the [[blastula]], during [[embryonic development]]. Animals form a [[clade]], meaning that they arose from a single common ancestor. [50] => [51] => Over 1.5 million [[extant taxon|living]] animal [[species]] have been [[species description|described]], of which around 1.05 million are [[insect]]s, over 85,000 are [[mollusc]]s, and around 65,000 are [[vertebrate]]s. It has been estimated there are as many as 7.77 million animal species on Earth. Animal body lengths range from {{cvt|8.5|μm|in}} to {{cvt|33.6|m|ft}}. They have complex [[ecologies]] and [[biological interaction|interaction]]s with each other and their environments, forming intricate [[food web]]s. The scientific study of animals is known as [[zoology]], and the study of animal behaviors is known as [[ethology]]. [52] => [53] => Most living animal species belong to the infrakingdom [[Bilateria]], a highly proliferative [[clade]] whose members have a [[symmetry in biology#Bilateral symmetry|bilaterally symmetric]] [[body plan]]. The vast majority belong to two large [[superphyla]]: the [[protostome]]s, which includes organisms such as the [[arthropod]]s, [[mollusc]]s, [[flatworm]]s, [[annelid]]s and [[nematode]]s; and the [[deuterostome]]s, which include the [[echinoderm]]s, [[hemichordate]]s and [[chordate]]s, the latter of which contains the vertebrates. The simple [[Xenacoelomorpha]] have an uncertain position within Bilateria. [54] => [55] => Animals first appear in the fossil record in the late [[Cryogenian]] period, and diversified in the subsequent [[Ediacaran]]. Earlier evidence of animals is still controversial; the [[sponge]]-like organism ''[[Otavia]]'' has been dated all the way back to the [[Tonian]] period, but its identity as an animal is heavily contested.{{cite journal|last1=Antcliffe|first1=Jonathan B.|last2=Callow|first2=Richard H. T.|last3=Brasier|first3=Martin D.|title=Giving the early fossil record of sponges a squeeze|journal=Biological Reviews|date=November 2014|volume=89|issue=4|pages=972–1004|doi=10.1111/brv.12090|pmid=24779547|s2cid=22630754 }} Nearly all modern animal phyla became clearly established in the fossil record as [[Marine life|marine species]] during the [[Cambrian explosion]], which began around 539 [[million years ago]] (Mya), and most [[class (biology)|class]]es during the [[Ordovician radiation]] 485.4 Mya. 6,331 groups of [[gene]]s common to all living animals have been identified; these may have arisen from a single [[#Phylogeny|common ancestor]] that lived about 650 Mya during the [[Cryogenian]] period. [56] => [57] => Historically, [[Aristotle]] divided animals [[Aristotle's biology|into those with blood and those without]]. [[Carl Linnaeus]] created the first hierarchical [[Taxonomy (biology)|biological classification]] for animals in 1758 with his ''[[Systema Naturae]]'', which [[Jean-Baptiste Lamarck]] expanded into 14 phyla by 1809. In 1874, [[Ernst Haeckel]] divided the animal kingdom into the multicellular '''Metazoa''' (now [[Synonym (taxonomy)|synonymous]] with Animalia) and the [[Protozoa]], single-celled organisms no longer considered animals. In modern times, the biological classification of animals relies on advanced techniques, such as [[molecular phylogenetics]], which are effective at demonstrating the [[evolution]]ary relationships between [[Taxon|taxa]]. [58] => [59] => [[Human]]s make [[human uses of animals|use of]] many other animal species for [[Human food|food]] (including [[meat]], [[eggs as food|egg]]s and [[dairy product]]s), for [[animal product|material]]s (such as [[leather]], [[fur]] and [[wool]]), as [[pet]]s and as [[working animal]]s for [[transportation]], and [[service (economics)|service]]s. [[Dog]]s, the first [[domesticate]]d animal, have been used [[hunting dog|in hunting]], [[guard dog|in security]] and [[dogs in warfare|in warfare]], as have [[equestrianism|horse]]s, [[pigeon post|pigeon]]s and [[falconry|birds of prey]], while other [[terrestrial animal |terrestrial]] and [[aquatic animal]]s are [[hunt]]ed for sports, trophies or profits. Non-human animals are also an important [[cultural]] element of [[human evolution]], having appeared in [[cave art]]s and [[totem]]s since the earliest times, and are frequently featured in [[mythology]], [[religion]], [[art]]s, [[literature]], [[heraldry]], [[politics]] and [[sport]]s. [60] => [61] => ==Etymology== [62] => [63] => [64] => The word ''animal'' comes from the Latin noun {{wiktlat|animal}} of the same meaning, which is itself derived from Latin {{wiktlat|animalis}} 'having breath or soul'.{{cite book |last=Cresswell |first=Julia |title=The Oxford Dictionary of Word Origins |year=2010 |publisher=[[Oxford University Press]] |location=New York |edition=2nd |isbn=978-0-19-954793-7 |quote='having the breath of life', from anima 'air, breath, life'.}} The biological definition includes all members of the kingdom Animalia.{{cite encyclopedia|title=Animal |encyclopedia=The American Heritage Dictionary |publisher=[[Houghton Mifflin]] |year=2006 |edition=4th}} In colloquial usage, the term ''animal'' is often used to refer only to nonhuman animals.{{cite web |website=English Oxford Living Dictionaries |title=animal |url=https://en.oxforddictionaries.com/definition/animal |access-date=26 July 2018 |archive-url=https://web.archive.org/web/20180726233938/https://en.oxforddictionaries.com/definition/animal |archive-date=26 July 2018 |url-status=dead}}{{cite journal |last1=Boly |first1=Melanie |last2=Seth |first2=Anil K. |last3=Wilke |first3=Melanie |last4=Ingmundson |first4=Paul |last5=Baars |first5=Bernard |last6=Laureys |first6=Steven |last7=Edelman |first7=David |last8=Tsuchiya |first8=Naotsugu |date=2013 |title=Consciousness in humans and non-human animals: recent advances and future directions |journal=[[Frontiers in Psychology]] |volume=4 |pages=625 |doi=10.3389/fpsyg.2013.00625 |pmc=3814086 |pmid=24198791|doi-access=free }}{{Cite web |website=[[Royal Society]] |url=https://royalsociety.org/topics-policy/publications/2004/non-human-animals/ |title=The use of non-human animals in research |access-date=7 June 2018 |archive-url=https://web.archive.org/web/20180612140908/https://royalsociety.org/topics-policy/publications/2004/non-human-animals/ |archive-date=12 June 2018 |url-status=live }}{{Cite web |url=https://www.collinsdictionary.com/dictionary/english/nonhuman |title=Nonhuman definition and meaning |website=Collins English Dictionary |access-date=7 June 2018 |archive-url=https://web.archive.org/web/20180612142932/https://www.collinsdictionary.com/dictionary/english/nonhuman |archive-date=12 June 2018 |url-status=live }} The term ''metazoa'' is derived from Ancient Greek μετα (''meta'') 'after' (in biology, the prefix ''meta-'' stands for 'later') and ζῷᾰ (''zōia'') 'animals', plural of ζῷον ''zōion'' 'animal'.{{cite dictionary |title=Metazoan |dictionary=Merriam-Webster |url=https://www.merriam-webster.com/dictionary/metazoan |access-date=6 July 2022 |archive-date=6 July 2022 |archive-url=https://web.archive.org/web/20220706115538/https://www.merriam-webster.com/dictionary/metazoan |url-status=live }}{{cite dictionary |title=Metazoa |dictionary=Collins |url=https://www.collinsdictionary.com/ko/dictionary/english/metazoa |access-date=6 July 2022 |archive-date=30 July 2022 |archive-url=https://web.archive.org/web/20220730091429/https://www.collinsdictionary.com/ko/dictionary/english/metazoa |url-status=live }} and further [https://www.collinsdictionary.com/ko/dictionary/english/meta meta- (sense 1)] {{Webarchive|url=https://web.archive.org/web/20220730091429/https://www.collinsdictionary.com/ko/dictionary/english/meta |date=30 July 2022 }} and [https://www.collinsdictionary.com/ko/dictionary/english/zoa -zoa] {{Webarchive|url=https://web.archive.org/web/20220730091429/https://www.collinsdictionary.com/ko/dictionary/english/zoa |date=30 July 2022 }}. [65] => [66] => == Characteristics == [67] => [68] => [[File:Blastulation.png|thumb|Animals are unique in having the ball of cells of the early [[embryo]] (1) develop into a hollow ball or [[blastula]] (2).]] [69] => [70] => Animals have several characteristics that set them apart from other living things. Animals are [[eukaryotic]] and [[multicellular]].{{cite book |last=Avila |first=Vernon L. |title=Biology: Investigating Life on Earth |url={{GBurl|id=B_OOazzGefEC|p=767}} |year=1995 |publisher=[[Jones & Bartlett Learning]] |isbn=978-0-86720-942-6 |pages=767–}} Unlike plants and [[alga]]e, which [[Autotroph|produce their own nutrients]],{{cite web |last=Davidson |first=Michael W. |title=Animal Cell Structure |url=https://micro.magnet.fsu.edu/cells/animalcell.html |access-date=20 September 2007 |archive-url=https://web.archive.org/web/20070920235924/https://micro.magnet.fsu.edu/cells/animalcell.html |archive-date=20 September 2007 |url-status=live}} animals are [[heterotroph]]ic,{{cite web |title=Palaeos:Metazoa |url=https://palaeos.com/metazoa/metazoa.html |website=Palaeos |access-date=25 February 2018 |archive-url=https://web.archive.org/web/20180228005641/https://palaeos.com/metazoa/metazoa.html |archive-date=28 February 2018 |url-status=dead }}{{cite web |last=Bergman |first=Jennifer |title=Heterotrophs |url=https://www.windows.ucar.edu/tour/link=/earth/Life/heterotrophs.html&edu=high |access-date=30 September 2007 |archive-url=https://web.archive.org/web/20070829051950/https://www.windows.ucar.edu/tour/link%3D/earth/Life/heterotrophs.html%26edu%3Dhigh |archive-date=29 August 2007 |url-status=dead}} feeding on organic material and digesting it internally.{{cite journal |last1=Douglas |first1=Angela E. |last2=Raven |first2=John A. |title=Genomes at the interface between bacteria and organelles |journal=[[Philosophical Transactions of the Royal Society B]] |volume=358 |issue=1429 |pages=5–17 |date=January 2003 |pmid=12594915 |pmc=1693093 |doi=10.1098/rstb.2002.1188}} With very few exceptions, animals [[aerobic respiration|respire aerobically]].{{efn|''[[Henneguya zschokkei]]'' does not have mitochondrial DNA or utilize aerobic respiration.{{Cite news |url= https://www.cnn.com/2020/02/26/world/first-animal-doesnt-breathe-oxygen-scn-trnd/index.html |title= Scientists discovered the first animal that doesn't need oxygen to live. It's changing the definition of what an animal can be |first= Scottie |last= Andrew |website= CNN |date= 26 February 2020 |access-date= 2020-02-28 |archive-date= 10 January 2022 |archive-url= https://web.archive.org/web/20220110180353/https://www.cnn.com/2020/02/26/world/first-animal-doesnt-breathe-oxygen-scn-trnd/index.html |url-status= live }}}}{{cite journal |last1=Mentel |first1=Marek |last2=Martin |first2=William |title=Anaerobic animals from an ancient, anoxic ecological niche |journal=BMC Biology |volume=8 |pages=32 |year=2010 |doi=10.1186/1741-7007-8-32 |pmid=20370917 |pmc=2859860 |doi-access=free }} All animals are [[Motility|motile]]{{cite web |url=https://employees.csbsju.edu/SSAUPE/biol116/Zoology/digestion.htm |last=Saupe |first=S. G. |title=Concepts of Biology |access-date=30 September 2007 |archive-url=https://web.archive.org/web/20071121084100/https://employees.csbsju.edu/SSAUPE/biol116/Zoology/digestion.htm |archive-date=21 November 2007 |url-status=live }} (able to spontaneously move their bodies) during at least part of their [[Biological life cycle|life cycle]], but some animals, such as [[sponge]]s, [[coral]]s, [[mussel]]s, and [[barnacle]]s, later become [[Sessility (motility)|sessile]]. The [[blastula]] is a stage in [[Embryogenesis|embryonic development]] that is unique to animals, allowing [[Cellular differentiation|cells to be differentiated]] into specialised tissues and organs.{{cite book |last=Minkoff |first=Eli C. |title=Barron's EZ-101 Study Keys Series: Biology |year=2008 |publisher=Barron's Educational Series |isbn=978-0-7641-3920-8 |edition=2nd, revised |page=48}} [71] => [72] => === Structure === [73] => [74] => All animals are composed of cells, surrounded by a characteristic [[extracellular matrix]] composed of [[collagen]] and elastic [[glycoprotein]]s.{{cite book |last1=Alberts |first1=Bruce |last2=Johnson |first2=Alexander |last3=Lewis |first3=Julian |last4=Raff |first4=Martin |last5=Roberts |first5=Keith |last6=Walter |first6=Peter |title=Molecular Biology of the Cell |edition=4th |year=2002 |publisher=[[Garland Science]] |url=https://www.ncbi.nlm.nih.gov/books/NBK26810/ |isbn=978-0-8153-3218-3 |access-date=29 August 2017 |archive-url=https://web.archive.org/web/20161223074013/https://www.ncbi.nlm.nih.gov/books/NBK26810/ |archive-date=23 December 2016 |url-status=live }} During development, the animal extracellular matrix forms a relatively flexible framework upon which cells can move about and be reorganised, making the formation of complex structures possible. This may be calcified, forming structures such as [[Exoskeleton|shells]], [[bone]]s, and [[spicule (sponge)|spicules]].{{cite book |last=Sangwal |first=Keshra |title=Additives and crystallization processes: from fundamentals to applications |url=https://archive.org/details/additivescrystal00sang |url-access=limited |year=2007 |publisher=[[John Wiley and Sons]] |isbn=978-0-470-06153-4 |page=[https://archive.org/details/additivescrystal00sang/page/n228 212]}} In contrast, the cells of other multicellular organisms (primarily algae, plants, and [[Fungus|fungi]]) are held in place by cell walls, and so develop by progressive growth.{{cite book |last=Becker |first=Wayne M. |title=The world of the cell |year=1991 |publisher=Benjamin/Cummings |isbn=978-0-8053-0870-9 |url=https://archive.org/details/worldofcell00beck_0 }} Animal cells uniquely possess the [[cell junction]]s called [[tight junction]]s, [[gap junction]]s, and [[desmosome]]s.{{cite book |last=Magloire |first=Kim |title=Cracking the AP Biology Exam, 2004–2005 Edition |year=2004 |publisher=[[The Princeton Review]] |isbn=978-0-375-76393-9 |page=[https://archive.org/details/crackingapbiolog00magl/page/45 45] |url=https://archive.org/details/crackingapbiolog00magl/page/45 }} [75] => [76] => With few exceptions—in particular, the sponges and [[placozoa]]ns—animal bodies are differentiated into [[biological tissue|tissues]].{{cite book |last=Starr |first=Cecie |url={{GBurl|id=EXNFwB-O-WUC|p=362}} |title=Biology: Concepts and Applications without Physiology |year=2007 |publisher=Cengage Learning |isbn=978-0-495-38150-1 |pages=362, 365 |access-date=19 May 2020 }} These include [[muscle]]s, which enable locomotion, and [[nerve tissue]]s, which transmit signals and coordinate the body. Typically, there is also an internal [[Digestion|digestive]] chamber with either one opening (in Ctenophora, Cnidaria, and flatworms) or two openings (in most bilaterians).{{cite book |last1=Hillmer |first1=Gero |last2=Lehmann |first2=Ulrich |others=Translated by J. Lettau |title=Fossil Invertebrates |year=1983 |publisher=CUP Archive |isbn=978-0-521-27028-1 |page=54 |url={{GBurl|id=9jE4AAAAIAAJ|p=54}} |access-date=8 January 2016 }} [77] => [78] => === Reproduction and development === [79] => [80] => {{see also|Sexual reproduction#Animals|Asexual reproduction#Examples in animals}} [81] => [82] => [[File:Odonata copulation.jpg|thumb|[[Sexual reproduction]] is nearly universal in animals, such as these [[Dragonfly|dragonflies]].]] [83] => [84] => Nearly all animals make use of some form of sexual reproduction.{{cite book |last=Knobil |first=Ernst |title=Encyclopedia of reproduction, Volume 1 |year=1998 |publisher=Academic Press |isbn=978-0-12-227020-8 |page=[https://archive.org/details/encyclopediaofre0000unse_f1r2/page/315 315] |url=https://archive.org/details/encyclopediaofre0000unse_f1r2/page/315 }} They produce [[haploid]] [[gamete]]s by [[meiosis]]; the smaller, motile gametes are [[Spermatozoon|spermatozoa]] and the larger, non-motile gametes are [[Egg cell|ova]].{{cite book |last=Schwartz |first=Jill |title=Master the GED 2011 |year=2010 |publisher=Peterson's |isbn=978-0-7689-2885-3 |page=[https://archive.org/details/petersonsmasterg0000stew_x3f1/page/371 371] |url=https://archive.org/details/petersonsmasterg0000stew_x3f1/page/371 }} These fuse to form [[zygote]]s,{{cite book |last=Hamilton |first=Matthew B. |title=Population genetics |url=https://archive.org/details/populationgeneti00hami |url-access=limited |year=2009 |publisher=[[Wiley-Blackwell]] |isbn=978-1-4051-3277-0 |page=[https://archive.org/details/populationgeneti00hami/page/n69 55]}} which develop via [[mitosis]] into a hollow sphere, called a blastula. In sponges, blastula larvae swim to a new location, attach to the seabed, and develop into a new sponge.{{cite book |last1=Ville |first1=Claude Alvin |last2=Walker |first2=Warren Franklin |last3=Barnes |first3=Robert D. |title=General zoology |year=1984 |publisher=Saunders College Pub |isbn=978-0-03-062451-3 |page=467}} In most other groups, the blastula undergoes more complicated rearrangement.{{cite book |last1=Hamilton |first1=William James |last2=Boyd |first2=James Dixon |last3=Mossman |first3=Harland Winfield |title=Human embryology: (prenatal development of form and function) |year=1945 |publisher=Williams & Wilkins |page=330}} It first [[Invagination|invaginates]] to form a [[gastrula]] with a digestive chamber and two separate [[germ layer]]s, an external [[ectoderm]] and an internal [[endoderm]].{{cite book |last=Philips |first=Joy B. |title=Development of vertebrate anatomy |year=1975 |publisher=Mosby |isbn=978-0-8016-3927-2 |page=[https://archive.org/details/developmentofver0000phil/page/176 176] |url=https://archive.org/details/developmentofver0000phil/page/176 }} In most cases, a third germ layer, the [[mesoderm]], also develops between them.{{cite book |title=The Encyclopedia Americana: a library of universal knowledge, Volume 10 |year=1918 |publisher=Encyclopedia Americana Corp. |page=281}} These germ layers then differentiate to form tissues and organs.{{cite book |last1=Romoser |first1=William S. |author-link1=William S. Romoser |last2=Stoffolano |first2=J. G. |title=The science of entomology |year=1998 |publisher=WCB McGraw-Hill |isbn=978-0-697-22848-2 |page=156}} [85] => [86] => Repeated instances of [[inbreeding|mating with a close relative]] during sexual reproduction generally leads to [[inbreeding depression]] within a population due to the increased prevalence of harmful [[Dominance (genetics)|recessive]] traits.{{cite journal |last1=Charlesworth |first1=D. |last2=Willis |first2=J. H. |title=The genetics of inbreeding depression |journal=[[Nature Reviews Genetics]] |volume=10 |issue=11 |pages=783–796 |year=2009 |pmid=19834483 |doi=10.1038/nrg2664|s2cid=771357 }}{{cite journal |last1=Bernstein |first1=H. |last2=Hopf |first2=F. A. |last3=Michod |first3=R. E. |title=The molecular basis of the evolution of sex |journal=Advances in Genetics |volume=24 |pages=323–370 |year=1987 |pmid=3324702 |doi=10.1016/s0065-2660(08)60012-7 |isbn=978-0-12-017624-3}} Animals have evolved numerous mechanisms for [[inbreeding avoidance|avoiding close inbreeding]].{{cite journal |last1=Pusey |first1=Anne |last2=Wolf |first2=Marisa |title=Inbreeding avoidance in animals |journal=Trends Ecol. Evol. |volume=11 |issue=5 |pages=201–206 |year=1996 |pmid=21237809 |doi=10.1016/0169-5347(96)10028-8}} [87] => [88] => Some animals are capable of [[asexual reproduction]], which often results in a genetic clone of the parent. This may take place through [[Fragmentation (reproduction)|fragmentation]]; [[budding]], such as in [[Hydra (genus)|''Hydra'']] and other [[cnidaria]]ns; or [[parthenogenesis]], where fertile eggs are produced without [[mating]], such as in [[aphid]]s.{{cite book |last1=Adiyodi |first1=K. G. |last2=Hughes |first2=Roger N. |last3=Adiyodi |first3=Rita G. |title=Reproductive Biology of Invertebrates, Volume 11, Progress in Asexual Reproduction |date=July 2002 |publisher=Wiley |page=116 |isbn=978-0-471-48968-9}}{{cite web |last1=Schatz |first1=Phil |title=Concepts of Biology: How Animals Reproduce |url=https://philschatz.com/biology-concepts-book/contents/m45547.html |publisher=OpenStax College |access-date=5 March 2018 |archive-url=https://web.archive.org/web/20180306022745/https://philschatz.com/biology-concepts-book/contents/m45547.html |archive-date=6 March 2018 |url-status=live }} [89] => [90] => == Ecology == [91] => [92] => [[File:Ultramarine Flycatcher (Ficedula superciliaris) Naggar, Himachal Pradesh, 2013 (cropped).JPG|thumb|upright|left|[[Predator]]s, such as this [[ultramarine flycatcher]] (''Ficedula superciliaris''), feed on other animals.]] [93] => [94] => Animals are categorised into ecological groups depending on their [[trophic level]]s and [[feeding behaviour|how they consume organic material]]. Such groupings include [[carnivore]]s (further divided into subcategories such as [[piscivore]]s, [[insectivore]]s, [[ovivore]]s, etc.), [[herbivore]]s (subcategorized into [[folivore]]s, [[graminivore]]s, [[frugivore]]s, [[granivore]]s, [[nectarivore]]s, [[algivore]]s, etc.), [[omnivore]]s, [[fungivore]]s, [[scavenger]]s/[[detritivore]]s,{{cite book |last1=Marchetti |first1=Mauro |last2=Rivas |first2=Victoria |title=Geomorphology and environmental impact assessment |year=2001 |publisher=Taylor & Francis |isbn=978-90-5809-344-8 |page=84}} and [[parasite]]s.{{cite book |last=Levy |first=Charles K. |title=Elements of Biology |year=1973 |publisher=[[Appleton-Century-Crofts]] |isbn=978-0-390-55627-1 |page=108}} [[Biological interaction|Interaction]]s between animals of each [[biome]] form complex [[food web]]s within that [[ecosystem]]. In carnivorous or omnivorous species, [[predation]] is a [[consumer-resource systems|consumer–resource interaction]] where the predator feeds on another organism, its [[prey]],{{cite book |last1=Begon |first1=M. |last2=Townsend |first2=C. |last3=Harper |first3=J. |date=1996 |title=Ecology: Individuals, populations and communities |edition=Third |publisher=Blackwell Science |isbn=978-0-86542-845-4 |url=https://archive.org/details/ecology00mich }} who often evolves [[anti-predator adaptation]]s to avoid being fed upon. [[Selective pressure]]s imposed on one another lead to an [[evolutionary arms race]] between predator and prey, resulting in various antagonistic/[[competition (biology)|competitive]] [[coevolution]]s.{{cite book |last1=Allen |first1=Larry Glen |last2=Pondella |first2=Daniel J. |last3=Horn |first3=Michael H. |title=Ecology of marine fishes: California and adjacent waters |year=2006 |publisher=[[University of California Press]] |isbn=978-0-520-24653-9 |page=428}}{{cite book |last=Caro |first=Tim |author-link=Tim Caro |title=Antipredator Defenses in Birds and Mammals |date=2005 |publisher=[[University of Chicago Press]] |pages=1–6 and passim}} Almost all multicellular predators are animals.{{cite journal |last1=Simpson |first1=Alastair G.B |last2=Roger |first2=Andrew J. |doi=10.1016/j.cub.2004.08.038 |pmid=15341755 |title=The real 'kingdoms' of eukaryotes |journal=Current Biology |volume=14 |issue=17 |pages=R693–696 |year=2004 |s2cid=207051421|doi-access=free }} Some [[consumer (food chain)|consumers]] use multiple methods; for example, in [[parasitoid wasp]]s, the larvae feed on the hosts' living tissues, killing them in the process,{{cite journal |last=Stevens |first=Alison N. P. |title=Predation, Herbivory, and Parasitism |journal=Nature Education Knowledge |date=2010 |volume=3 |issue=10 |page=36 |url=https://www.nature.com/scitable/knowledge/library/predation-herbivory-and-parasitism-13261134 |access-date=12 February 2018 |archive-url=https://web.archive.org/web/20170930230324/https://www.nature.com/scitable/knowledge/library/predation-herbivory-and-parasitism-13261134 |archive-date=30 September 2017 |url-status=live }} but the adults primarily consume nectar from flowers.{{Cite journal |last1=Jervis |first1=M. A. |last2=Kidd |first2=N. A. C. |date=November 1986 |title=Host-Feeding Strategies in Hymenopteran Parasitoids |journal=Biological Reviews |volume=61 |issue=4 |pages=395–434 |doi=10.1111/j.1469-185x.1986.tb00660.x|s2cid=84430254 }} Other animals may have very specific [[feeding behaviour]]s, such as [[hawksbill sea turtle]]s which mainly [[Spongivore|eat sponges]].{{cite journal |last=Meylan |first=Anne |title=Spongivory in Hawksbill Turtles: A Diet of Glass |journal=Science |volume=239 |issue=4838 |pages=393–395 |date=22 January 1988 |doi=10.1126/science.239.4838.393| pmid=17836872 |jstor=1700236| bibcode=1988Sci...239..393M |s2cid=22971831}} [95] => [96] => [[File:Expl0072 - Flickr - NOAA Photo Library.jpg|thumb|[[Hydrothermal vent]] mussels and shrimps]] [97] => Most animals rely on [[biomass]] and [[biological energy|bioenergy]] produced by [[plant]]s and [[phytoplankton]]s (collectively called [[producer (biology)|producer]]s) through [[photosynthesis]]. Herbivores, as [[consumer (food chain)#Levels of the food chain|primary consumer]]s, eat the plant material directly to digest and absorb the nutrients, while carnivores and other animals on higher [[trophic level]]s indirectly acquire the nutrients by eating the herbivores or other animals that have eaten the herbivores. Animals oxidize [[carbohydrate]]s, [[lipid]]s, [[protein]]s and other biomolecules, which allows the animal to grow and to sustain [[basal metabolism]] and fuel other biological processes such as [[animal locomotion|locomotion]].{{cite book |title=Understanding Science: Upper Primary |last=Clutterbuck |first=Peter |year=2000 |publisher=Blake Education |isbn=978-1-86509-170-9 |page=9}}{{cite book |last=Gupta |first=P. K. |title=Genetics Classical To Modern |publisher=Rastogi Publications |isbn=978-81-7133-896-2 |page=26|year=1900 }}{{cite book |last1=Garrett |first1=Reginald |last2=Grisham |first2=Charles M. |title=Biochemistry |url=https://archive.org/details/biochemistry00rhga |url-access=limited |year=2010 |publisher=Cengage Learning |isbn=978-0-495-10935-8 |page=[https://archive.org/details/biochemistry00rhga/page/n572 535]}} Some [[benthic]] animals living close to [[hydrothermal vent]]s and [[cold seep]]s on the dark [[seabed|sea floor]] consume organic matter produced through [[chemosynthesis]] (via [[oxidizing]] [[inorganic compound]]s such as [[hydrogen sulfide]]) by [[archaea]] and [[bacteria]].{{cite book |last1=Castro |first1=Peter |last2=Huber |first2=Michael E. |title=Marine Biology |publisher=McGraw-Hill |year=2007 |edition=7th |page=376 |isbn=978-0-07-722124-9}} [98] => [99] => Animals evolved in the sea. Lineages of arthropods colonised land around the same time as [[land plant]]s, probably between 510 and 471 million years ago during the [[Late Cambrian]] or Early [[Ordovician]].{{cite journal |last1=Rota-Stabelli |first1=Omar |last2=Daley |first2=Allison C. |last3=Pisani |first3=Davide |title=Molecular Timetrees Reveal a Cambrian Colonization of Land and a New Scenario for Ecdysozoan Evolution |journal=Current Biology |volume=23 |issue=5 |pages=392–8 |year=2013 |doi-access=free |doi=10.1016/j.cub.2013.01.026 |pmid=23375891}} [[Vertebrate]]s such as the [[Sarcopterygii|lobe-finned fish]] ''[[Tiktaalik]]'' started to move on to land in the late [[Devonian]], about 375 million years ago.{{cite journal |last1=Daeschler |first1=Edward B. |last2=Shubin |first2=Neil H. |last3=Jenkins |first3=Farish A. Jr. |title=A Devonian tetrapod-like fish and the evolution of the tetrapod body plan |journal=[[Nature (journal)|Nature]] |volume=440 |pages=757–763 |date=6 April 2006 |doi=10.1038/nature04639 |pmid=16598249 |issue=7085 |bibcode=2006Natur.440..757D |doi-access=free }}{{cite journal |author-link=Jennifer A. Clack |last=Clack |first=Jennifer A. |journal=[[Scientific American]] |volume=293 |issue=6 |pages=100–7 |title=Getting a Leg Up on Land |date=21 November 2005 |bibcode=2005SciAm.293f.100C |doi=10.1038/scientificamerican1205-100 |pmid=16323697 }} Animals occupy virtually all of earth's [[habitat]]s and microhabitats, with [[fauna]]s adapted to salt water, hydrothermal vents, fresh water, hot springs, swamps, forests, pastures, deserts, air, and the interiors of other organisms.{{cite book |last=Margulis |first=Lynn |author1-link=Lynn Margulis |author2=Schwartz, Karlene V. |author3=Dolan, Michael |title=Diversity of Life: The Illustrated Guide to the Five Kingdoms |url={{GBurl|id=8wJXWBMsEOkC|p=115}} |year=1999 |publisher=Jones & Bartlett Learning |isbn=978-0-7637-0862-7 |pages=115–116}} Animals are however not particularly [[Thermophile|heat tolerant]]; very few of them can survive at constant temperatures above {{convert|50|°C|0|abbr=on}}{{cite journal |last=Clarke |first=Andrew |title=The thermal limits to life on Earth |journal=International Journal of Astrobiology |volume=13 |issue=2 |pages=141–154 |year=2014 |bibcode=2014IJAsB..13..141C |url=https://nora.nerc.ac.uk/id/eprint/507274/1/Clarke.pdf |archive-url=https://web.archive.org/web/20190424155004/https://nora.nerc.ac.uk/id/eprint/507274/1/Clarke.pdf |archive-date=24 April 2019 |url-status=live |doi=10.1017/S1473550413000438|doi-access=free }} or in the most extreme cold deserts of continental [[Antarctica]].{{cite web |title=Land animals |url=https://www.bas.ac.uk/about/antarctica/wildlife/land-animals/ |publisher=[[British Antarctic Survey]] |access-date=7 March 2018 |archive-url=https://web.archive.org/web/20181106225451/https://www.bas.ac.uk/about/antarctica/wildlife/land-animals/ |archive-date=6 November 2018 |url-status=live}} [100] => [101] => == Diversity == [102] => [103] => === Size === [104] => [105] => {{further|Largest organisms|Smallest organisms}} [106] => [107] => [[File:Anim1754 - Flickr - NOAA Photo Library (1).jpg|thumb|The [[blue whale]] is the largest animal that has ever lived.]] [108] => [109] => The [[blue whale]] (''Balaenoptera musculus'') is the largest animal that has ever lived, weighing up to 190 [[tonne]]s and measuring up to {{convert|33.6|m|ft}} long.{{cite book |last=Wood |first=Gerald |title=The Guinness Book of Animal Facts and Feats |year=1983 |isbn=978-0-85112-235-9 |url=https://archive.org/details/guinnessbookofan00wood |publisher=Enfield, Middlesex : Guinness Superlatives }}{{cite web |last1=Davies |first1=Ella |title=The longest animal alive may be one you never thought of |url=https://www.bbc.com/earth/story/20160420-the-longest-animal-alive-may-not-be-the-blue-whale |website=BBC Earth |access-date=1 March 2018 |date=20 April 2016 |archive-url=https://web.archive.org/web/20180319073808/https://www.bbc.com/earth/story/20160420-the-longest-animal-alive-may-not-be-the-blue-whale |archive-date=19 March 2018 |url-status=live }}{{cite web |url=https://www.guinnessworldrecords.com/world-records/largest-mammal |title=Largest mammal |publisher=Guinness World Records |access-date=1 March 2018 |archive-url=https://web.archive.org/web/20180131024019/https://www.guinnessworldrecords.com/world-records/largest-mammal |archive-date=31 January 2018 |url-status=live }} The largest extant terrestrial animal is the [[African bush elephant]] (''Loxodonta africana''), weighing up to 12.25 tonnes and measuring up to {{convert|10.67|m|ft}} long. The largest terrestrial animals that ever lived were [[titanosaur]] [[Sauropoda|sauropod dinosaurs]] such as ''[[Argentinosaurus]]'', which may have weighed as much as 73 tonnes, and ''Supersaurus'' which may have reached 39 meters.{{cite journal |last=Mazzetta |first=Gerardo V. |author2=Christiansen, Per |author3=Fariña, Richard A. |year=2004 |title=Giants and Bizarres: Body Size of Some Southern South American Cretaceous Dinosaurs |journal=Historical Biology |volume=16 |issue= 2–4 |pages=71–83 |doi=10.1080/08912960410001715132 |bibcode=2004HBio...16...71M |citeseerx=10.1.1.694.1650 |s2cid=56028251 }}{{Cite web |last=Curtice |first=Brian |date=2020 |title=Society of Vertebrate Paleontology |url=https://vertpaleo.org/wp-content/uploads/2021/10/SVP_2021_VirtualBook_final.pdf#page=92 |website=Vertpaleo.org |access-date=30 December 2022 |archive-date=19 October 2021 |archive-url=https://web.archive.org/web/20211019192436/https://vertpaleo.org/wp-content/uploads/2021/10/SVP_2021_VirtualBook_final.pdf#page=92 |url-status=live }} Several animals are microscopic; some [[Myxozoa]] ([[obligate parasite]]s within the Cnidaria) never grow larger than 20 [[Micrometre|μm]],{{cite web |url=https://tolweb.org/Myxozoa/2460/2008.07.10 |title=Myxozoa |last=Fiala |first=Ivan |date=10 July 2008 |publisher=Tree of Life Web Project |access-date=4 March 2018 |archive-url=https://web.archive.org/web/20180301225416/https://tolweb.org/Myxozoa/2460/2008.07.10 |archive-date=1 March 2018 |url-status=live }} and one of the smallest species (''Myxobolus shekel'') is no more than 8.5 μm when fully grown.{{cite journal |last1=Kaur |first1=H. |last2=Singh |first2=R. |title=Two new species of Myxobolus (Myxozoa: Myxosporea: Bivalvulida) infecting an Indian major carp and a cat fish in wetlands of Punjab, India |pmc=3235390 |pmid=23024499 |doi=10.1007/s12639-011-0061-4 |volume=35 |issue=2 |year=2011 |journal=Journal of Parasitic Diseases |pages=169–176}} [110] => [111] => === Numbers and habitats of major phyla === [112] => [113] => [114] => The following table lists estimated numbers of described extant species for the major animal phyla,{{cite journal |last=Zhang |first=Zhi-Qiang |title=Animal biodiversity: An update of classification and diversity in 2013. In: Zhang, Z.-Q. (Ed.) Animal Biodiversity: An Outline of Higher-level Classification and Survey of Taxonomic Richness (Addenda 2013) |journal=Zootaxa |volume=3703 |issue=1 |date=2013-08-30 |doi=10.11646/zootaxa.3703.1.3 |url=https://biotaxa.org/Zootaxa/article/download/zootaxa.3703.1.3/4273 |page=5 |access-date=2 March 2018 |archive-url=https://web.archive.org/web/20190424154926/https://biotaxa.org/Zootaxa/article/download/zootaxa.3703.1.3/4273 |archive-date=24 April 2019 |url-status=live |doi-access=free }} along with their principal habitats (terrestrial, fresh water,{{cite book |last1=Balian |first1=E. V. |last2=Lévêque |first2=C. |last3=Segers|first3=H.|first4=K. |last4=Martens |title=Freshwater Animal Diversity Assessment |url={{GBurl|id=Dw4H6DBHnAgC|p=628}} |year=2008 |publisher=Springer |isbn=978-1-4020-8259-7 |page=628}} and marine),{{cite web |last1=Hogenboom |first1=Melissa |title=There are only 35 kinds of animal and most are really weird |url=https://www.bbc.co.uk/earth/story/20150325-all-animal-life-in-35-photos |publisher=BBC Earth |access-date=2 March 2018 |archive-url=https://web.archive.org/web/20180810141811/https://www.bbc.co.uk/earth/story/20150325-all-animal-life-in-35-photos|archive-date=10 August 2018|url-status=live}} and free-living or parasitic ways of life.{{cite book |last=Poulin |first=Robert |author-link=Robert Poulin (zoologist) |title=Evolutionary Ecology of Parasites |publisher=[[Princeton University Press]] |year=2007 |isbn=978-0-691-12085-0 |page=[https://archive.org/details/evolutionaryecol0000poul/page/6 6] |url=https://archive.org/details/evolutionaryecol0000poul/page/6 }} Species estimates shown here are based on numbers described scientifically; much larger estimates have been calculated based on various means of prediction, and these can vary wildly. For instance, around 25,000–27,000 species of nematodes have been described, while published estimates of the total number of nematode species include 10,000–20,000; 500,000; 10 million; and 100 million.{{cite book |last1=Felder |first1=Darryl L. |last2=Camp |first2=David K. |title=Gulf of Mexico Origin, Waters, and Biota: Biodiversity |url={{GBurl|id=CphA8hiwaFIC|pg=RA1-PA1111}} |year=2009 |publisher=Texas A&M University Press |isbn=978-1-60344-269-5 |page=1111}} Using patterns within the [[taxonomy (biology)|taxonomic]] hierarchy, the total number of animal species—including those not yet described—was calculated to be about 7.77 million in 2011.{{cite web |title=How many species on Earth? About 8.7 million, new estimate says |url=https://www.sciencedaily.com/releases/2011/08/110823180459.htm |access-date=2 March 2018 |date=24 August 2011 |archive-url=https://web.archive.org/web/20180701164954/https://www.sciencedaily.com/releases/2011/08/110823180459.htm |archive-date=1 July 2018 |url-status=live }}{{cite journal |last1=Mora |first1=Camilo |last2=Tittensor |first2=Derek P. |last3=Adl |first3=Sina |last4=Simpson |first4=Alastair G.B. |last5=Worm |first5=Boris |editor-last=Mace |editor-first=Georgina M. |title=How Many Species Are There on Earth and in the Ocean? |journal=PLOS Biology |volume=9 |issue=8 |date=2011-08-23 |doi=10.1371/journal.pbio.1001127 |page=e1001127 |pmid=21886479 |pmc=3160336 |doi-access=free }}{{efn|The application of [[DNA barcoding]] to taxonomy further complicates this; a 2016 barcoding analysis estimated a total count of nearly 100,000 [[insect]] species for [[Canada]] alone, and extrapolated that the global insect fauna must be in excess of 10 million species, of which nearly 2 million are in a single fly family known as gall midges ([[Cecidomyiidae]]).{{cite journal |last1=Hebert |first1=Paul D.N. |last2=Ratnasingham |first2=Sujeevan |last3=Zakharov |first3=Evgeny V. |last4=Telfer |first4=Angela C. |last5=Levesque-Beaudin |first5=Valerie |last6=Milton |first6=Megan A. |last7=Pedersen |first7=Stephanie |last8=Jannetta |first8=Paul |last9=deWaard |first9=Jeremy R. |title=Counting animal species with DNA barcodes: Canadian insects |journal=Philosophical Transactions of the Royal Society B: Biological Sciences |date=1 August 2016 |volume=371 |issue=1702 |pages=20150333 |doi=10.1098/rstb.2015.0333 |pmid=27481785 |pmc=4971185}}}} [115] => [116] => {|class="wikitable sortable" [117] => |- [118] => ! [[Phylum]] [119] => ! class="unsortable" | Example [120] => ! Described species [121] => ! [[Terrestrial animal|Land]] [122] => ! [[Marine animals|Sea]] [123] => ! [[Fresh water#Aquatic organisms|Freshwater]] [124] => ! Free-living [125] => ! [[Parasite|Parasitic]] [126] => [127] => |- [128] => |'''[[Arthropoda]]''' [129] => |[[File:European wasp white bg02.jpg|alt=wasp|100px]] [130] => |align=right data-sort-value="1257000"|1,257,000 [131] => |Yes 1,000,000
([[insect]]s){{cite journal |last=Stork |first=Nigel E. |s2cid=23755007 |title=How Many Species of Insects and Other Terrestrial Arthropods Are There on Earth? |journal=Annual Review of Entomology |volume=63 |issue=1 |date=January 2018 |doi=10.1146/annurev-ento-020117-043348 |pmid=28938083 |pages=31–45 |doi-access=free }} Stork notes that 1m insects have been named, making much larger predicted estimates. [132] => |Yes >40,000
([[Malacostraca|Malac-
ostraca]]){{cite book |year=2002 |series=Zoological catalogue of Australia |volume=19.2A |title=Crustacea: Malacostraca |publisher=[[CSIRO Publishing]] |isbn=978-0-643-06901-5 |chapter=Introduction |last=Poore |first=Hugh F. |pages=1–7 |chapter-url={{GBurl|id=ww6RzBz42-4C|p=1}}}} [133] => |Yes 94,000 [134] => |Yes [135] => |Yes >45,000{{efn|Not including [[parasitoid]]s.}} [136] => [137] => |- [138] => |'''[[Mollusca]]''' [139] => |[[File:Grapevinesnail 01.jpg|alt=snail|100px]] [140] => |align=right data-sort-value="85000" |85,000
107,000 [141] => |Yes 35,000{{cite journal |last=Nicol |first=David |title=The Number of Living Species of Molluscs |journal=Systematic Zoology |volume=18 |issue=2 |date=June 1969 |pages=251–254 |doi=10.2307/2412618 |jstor=2412618 |doi-access=free }} [142] => |Yes 60,000 [143] => |Yes 5,000
12,000 [144] => |Yes [145] => |Yes >5,600 [146] => [147] => |- [148] => |'''[[Chordata]]''' [149] => |[[File:Lithobates pipiens.jpg|alt=green spotted frog facing right|100px]] [150] => |align=right data-sort-value="70000"|>70,000{{Cite journal|last=Uetz|first=P.|title=A Quarter Century of Reptile and Amphibian Databases|url=https://www.researchgate.net/publication/352462027|journal=Herpetological Review|volume=52|pages=246–255|via=ResearchGate|access-date=2 October 2021|archive-date=21 February 2022|archive-url=https://web.archive.org/web/20220221154655/https://www.researchgate.net/publication/352462027_A_Quarter_Century_of_Reptile_and_Amphibian_Databases|url-status=live}} [151] => |Yes 23,000{{cite book |last1=Reaka-Kudla |first1=Marjorie L. |last2=Wilson |first2=Don E. |last3=Wilson |first3=Edward O. |author3-link=E. O. Wilson |title=Biodiversity II: Understanding and Protecting Our Biological Resources |url={{GBurl|id=-X5OAgAAQBAJ|p=90}} |year=1996 |publisher=Joseph Henry Press |isbn=978-0-309-52075-1 |page=90}} [152] => |Yes 13,000 [153] => |Yes 18,000
9,000 [154] => |Yes [155] => |Yes 40
([[catfish]]){{cite book |last1=Burton |first1=Derek |last2=Burton |first2=Margaret |title=Essential Fish Biology: Diversity, Structure and Function |url={{GBurl|id=U0o4DwAAQBAJ|p=281}} |year=2017 |publisher=Oxford University Press |isbn=978-0-19-878555-2 |pages=281–282 |quote=[[Trichomycteridae]] ... includes obligate parasitic fish. Thus 17 genera from 2 subfamilies, [[Vandelliinae]]; 4 genera, 9spp. and [[Stegophilinae]]; 13 genera, 31 spp. are parasites on gills (Vandelliinae) or skin (stegophilines) of fish.}} [156] => [157] => |- [158] => |'''[[Platyhelminthes]]''' [159] => |[[File:Pseudoceros dimidiatus.jpg|100px]] [160] => |align=right data-sort-value="29500"|29,500 [161] => |Yes{{Cite journal |last=Sluys |first=R. |title=Global diversity of land planarians (Platyhelminthes, Tricladida, Terricola): a new indicator-taxon in biodiversity and conservation studies|journal=Biodiversity and Conservation |volume=8 |issue=12 |pages=1663–1681 |doi=10.1023/A:1008994925673 |year=1999|s2cid=38784755 }} [162] => |Yes [163] => |Yes 1,300 [164] => |Yes
[165] => 3,000–6,500{{cite book |last=Pandian |first=T. J. |title=Reproduction and Development in Platyhelminthes |publisher=CRC Press |year=2020 |isbn=978-1-000-05490-3 |pages=13–14 |url={{GBurl|id=l6rMDwAAQBAJ|pg=PT14}} |access-date=19 May 2020 }} [166] => |Yes >40,000
[167] => 4,000–25,000 [168] => [169] => |- [170] => |'''[[Nematoda]]''' [171] => |[[File:CelegansGoldsteinLabUNC.jpg|100px]] [172] => |align=right data-sort-value="25000"|25,000 [173] => |Yes (soil) [174] => |Yes 4,000 [175] => |Yes 2,000 [176] => |Yes
11,000 [177] => |Yes 14,000 [178] => [179] => |- [180] => |'''[[Annelida]]''' [181] => |[[File:Nerr0328.jpg|100px]] [182] => |align=right |17,000 [183] => |Yes (soil) [184] => |Yes [185] => |Yes 1,750 [186] => |Yes [187] => |Yes 400 [188] => [189] => |- [190] => |'''[[Cnidaria]]''' [191] => |[[File:FFS Table bottom.jpg|alt=Table coral|100px]] [192] => |align=right data-sort-value="16000"|16,000 [193] => | [194] => |Yes [195] => |Yes (few) [196] => |Yes [197] => |Yes >1,350
([[Myxozoa]]) [198] => [199] => |- [200] => |'''[[Porifera]]''' [201] => |[[File:A colourful Sponge on the Fathom.jpg|100px]] [202] => |align=right data-sort-value="10800"|10,800 [203] => | [204] => |Yes [205] => |200–300 [206] => |Yes [207] => |Yes{{cite book |last1=Morand |first1=Serge |last2=Krasnov |first2=Boris R. |last3=Littlewood |first3=D. Timothy J. |title=Parasite Diversity and Diversification |url={{GBurl|id=o2t2BgAAQBAJ|p=44}} |year=2015 |publisher=Cambridge University Press |isbn=978-1-107-03765-6 |page=44 |access-date=2 March 2018 }} [208] => [209] => |- [210] => |'''[[Echinodermata]]''' [211] => |[[File:Starfish, Caswell Bay - geograph.org.uk - 409413.jpg|100px]] [212] => |align=right data-sort-value="7500"|7,500 [213] => | [214] => |Yes 7,500 [215] => | [216] => |Yes [217] => | [218] => [219] => |- [220] => |'''[[Bryozoa]]''' [221] => |[[File:Bryozoan at Ponta do Ouro, Mozambique (6654415783).jpg|100px]] [222] => |align=right data-sort-value="6000" |6,000 [223] => | [224] => |Yes [225] => |Yes 60–80 [226] => |Yes [227] => | [228] => [229] => |- [230] => |'''[[Rotifera]]''' [231] => |[[File:20090730 020239 Rotifer.jpg|100px]] [232] => |align=right data-sort-value="2000"|2,000 [233] => | [234] => |Yes >400{{cite web |last=Fontaneto |first=Diego |title=Marine Rotifers {{!}} An Unexplored World of Richness |url=https://ukmarinesac.org.uk/PDF/rotifers.pdf |publisher=JMBA Global Marine Environment |access-date=2 March 2018 |pages=4–5 |archive-url=https://web.archive.org/web/20180302225409/https://ukmarinesac.org.uk/PDF/rotifers.pdf |archive-date=2 March 2018 |url-status=live }} [235] => |Yes 2,000 [236] => |Yes [237] => | [238] => [239] => |- [240] => |'''[[Nemertea]]''' [241] => |[[File:Némerte.jpg|100px]] [242] => |align=right data-sort-value="1350"|1,350{{cite journal |last1=Chernyshev |first1=A. V. |title=An updated classification of the phylum Nemertea |journal=Invertebrate Zoology |date=September 2021 |volume=18 |issue=3 |pages=188–196 |doi=10.15298/invertzool.18.3.01 |s2cid=239872311 |url=https://www.researchgate.net/publication/354810461 |access-date=18 January 2023 |doi-access=free }}{{cite journal |last1=Hookabe |first1=Natsumi |last2=Kajihara |first2=Hiroshi |last3=Chernyshev |first3=Alexei V. |last4=Jimi |first4=Naoto |last5=Hasegawa |first5=Naohiro |last6=Kohtsuka |first6=Hisanori |last7=Okanishi |first7=Masanori |last8=Tani |first8=Kenichiro |last9=Fujiwara |first9=Yoshihiro |last10=Tsuchida |first10=Shinji |last11=Ueshima |first11=Rei |title=Molecular Phylogeny of the Genus Nipponnemertes (Nemertea: Monostilifera: Cratenemertidae) and Descriptions of 10 New Species, With Notes on Small Body Size in a Newly Discovered Clade |journal=Frontiers in Marine Science |date=2022 |volume=9 |doi=10.3389/fmars.2022.906383 |url=https://www.researchgate.net/publication/362813258 |access-date=18 January 2023 |doi-access=free }} [243] => | [244] => |Yes [245] => |Yes [246] => |Yes [247] => | [248] => [249] => |- [250] => |'''[[Tardigrada]]''' [251] => |[[File:Tardigrade (50594282802).jpg|100px]] [252] => |align=right data-sort-value="1335"|1,335 [253] => |Yes{{cite book |title=Animal Diversity |first1=Cleveland P. |last1=Hickman |first2=Susan L. |last2=Keen |first3=Allan |last3=Larson |first4=David J. |last4=Eisenhour |edition=8th |publisher=McGraw-Hill Education |date=2018 |isbn=978-1-260-08427-6}}
(moist plants) [254] => |Yes [255] => |Yes [256] => |Yes [257] => | [258] => |- [259] => ! colspan=8 |{{centre|Total number of described extant species {{as of|2013|lc=y}}: 1,525,728}} [260] => |} [261] => [262] => == Evolutionary origin == [263] => [264] => {{Further|Urmetazoan}} [265] => [266] => Evidence of animals is found as long ago as the [[Cryogenian]] period. [[24-Isopropylcholestane]] (24-ipc) has been found in rocks from roughly 650 million years ago; it is only produced by sponges and [[Pelagophycidae|pelagophyte]] algae. Its likely origin is from sponges based on [[molecular clock]] estimates for the origin of 24-ipc production in both groups. Analyses of pelagophyte algae consistently recover a [[Phanerozoic]] origin, while analyses of sponges recover a [[Neoproterozoic]] origin, consistent with the appearance of 24-ipc in the fossil record.{{cite journal |last1=Gold |first1=David |display-authors=et al. |title=Sterol and genomic analyses validate the sponge biomarker hypothesis |journal=PNAS |date=22 February 2016 |doi=10.1073/pnas.1512614113 |url=https://www.pnas.org/doi/full/10.1073/pnas.1512614113#sec-1|pmc=4790988 }}{{cite journal |last1=Love |first1=Gordon |display-authors=et al. |title=Fossil steroids record the appearance of Demospongiae during the Cryogenian period |journal=Nature |date=5 February 2009 |doi=10.1038/nature07673}} [267] => [268] => The first body fossils of animals appear in the [[Ediacaran]], represented by forms such as ''[[Charnia]]'' and ''[[Spriggina]]''. It had long been doubted whether these fossils truly represented animals,{{cite journal |last1=Shen |first1=Bing |last2=Dong |first2=Lin |last3=Xiao |first3=Shuhai |last4=Kowalewski |first4=Michał |year=2008 |title=The Avalon Explosion: Evolution of Ediacara Morphospace |journal=Science |volume=319 |issue=5859 |pages=81–84 |doi=10.1126/science.1150279 |pmid=18174439 |bibcode=2008Sci...319...81S |s2cid=206509488 }}{{cite journal |title=Late Ediacaran trackways produced by bilaterian animals with paired appendages |first1=Zhe |last1=Chen |first2=Xiang |last2=Chen |first3=Chuanming |last3=Zhou |first4=Xunlai |last4=Yuan |first5=Shuhai |last5=Xiao |date=1 June 2018 |journal=Science Advances |volume=4 |issue=6 |pages=eaao6691 |doi=10.1126/sciadv.aao6691 |pmid=29881773 |pmc=5990303 |bibcode=2018SciA....4.6691C }}{{cite book |last=Schopf |first=J. William |title=Evolution!: facts and fallacies |year=1999 |publisher=Academic Press |isbn=978-0-12-628860-5 |page=[https://archive.org/details/evolutionfactsfa0000unse/page/7 7] |url=https://archive.org/details/evolutionfactsfa0000unse/page/7 }} but the discovery of the animal lipid [[cholesterol]] in fossils of ''[[Dickinsonia]]'' establishes their nature. Animals are thought to have originated under low-oxygen conditions, suggesting that they were capable of living entirely by [[anaerobic respiration]], but as they became specialized for aerobic metabolism they became fully dependent on oxygen in their environments.{{cite journal |last1=Zimorski |first1=Verena |last2=Mentel |first2=Marek |last3=Tielens |first3=Aloysius G. M. |last4=Martin |first4=William F. |title=Energy metabolism in anaerobic eukaryotes and Earth's late oxygenation |journal=Free Radical Biology and Medicine |volume=140 |pages=279–294 |year=2019 |doi=10.1016/j.freeradbiomed.2019.03.030 |pmid=30935869 |pmc=6856725 }} [269] => [270] => Many animal phyla first appear in the [[fossil]] record during the [[Cambrian explosion]], starting about 539 million years ago, in beds such as the [[Burgess shale]].{{cite web |title=Stratigraphic Chart 2022 |url=https://stratigraphy.org/ICSchart/ChronostratChart2022-02.pdf |publisher=International Stratigraphic Commission |date=February 2022 |access-date=25 April 2022 |archive-date=2 April 2022 |archive-url=https://web.archive.org/web/20220402100018/https://stratigraphy.org/ICSchart/ChronostratChart2022-02.pdf |url-status=live }} Extant phyla in these rocks include [[mollusc]]s, [[brachiopod]]s, [[onychophora]]ns, [[tardigrade]]s, [[arthropod]]s, [[echinoderm]]s and [[hemichordate]]s, along with numerous now-extinct forms such as the [[predator]]y ''[[Anomalocaris]]''. The apparent suddenness of the event may however be an artifact of the fossil record, rather than showing that all these animals appeared simultaneously.{{cite journal |last1=Maloof |first1=A. C. |last2=Porter |first2=S. M. |last3=Moore |first3=J. L. |last4=Dudas |first4=F. O. |last5=Bowring |first5=S. A. |last6=Higgins |first6=J. A. |last7=Fike |first7=D. A. |last8=Eddy |first8=M. P. |s2cid=6694681 |title=The earliest Cambrian record of animals and ocean geochemical change |journal=Geological Society of America Bulletin |year=2010 |volume=122 |issue=11–12 |pages=1731–1774 |doi=10.1130/B30346.1 |bibcode=2010GSAB..122.1731M }}{{cite web |title=New Timeline for Appearances of Skeletal Animals in Fossil Record Developed by UCSB Researchers |url=https://www.ia.ucsb.edu/pa/display.aspx?pkey=2364 |publisher=The Regents of the University of California |access-date=1 September 2014 |date=10 November 2010 |archive-url=https://web.archive.org/web/20140903062054/https://www.ia.ucsb.edu/pa/display.aspx?pkey=2364 |archive-date=3 September 2014 |url-status=live }}{{cite journal |last=Conway-Morris |first=Simon |author-link=Simon Conway Morris |title=The Cambrian "explosion" of metazoans and molecular biology: would Darwin be satisfied? |journal=The International Journal of Developmental Biology |year=2003 |volume=47 |issue=7–8 |pages=505–515 |pmid=14756326 |url=https://www.ijdb.ehu.es/web/paper.php?doi=14756326 |access-date=28 February 2018 |archive-url=https://web.archive.org/web/20180716111730/https://www.ijdb.ehu.es/web/paper.php?doi=14756326 |archive-date=16 July 2018 |url-status=live }}{{cite web |title=The Tree of Life |url=https://burgess-shale.rom.on.ca/en/science/origin/01-life-tree.php |website=The Burgess Shale |publisher=[[Royal Ontario Museum]] |access-date=28 February 2018 |archive-url=https://web.archive.org/web/20180216054845/https://burgess-shale.rom.on.ca/en/science/origin/01-life-tree.php |archive-date=16 February 2018 |url-status=live |date=10 June 2011}} That view is supported by the discovery of ''[[Auroralumina attenboroughii]]'', the earliest known Ediacaran crown-group cnidarian (557–562 mya, some 20 million years before the Cambrian explosion) from [[Charnwood Forest]], England. It is thought to be one of the earliest [[Predation|predator]]s, catching small prey with its [[nematocyst]]s as modern cnidarians do.{{cite journal |last1=Dunn |first1=F. S. |last2=Kenchington |first2=C. G. |last3=Parry |first3=L. A. |last4=Clark |first4=J. W. |last5=Kendall |first5=R. S. |last6=Wilby |first6=P. R. |title=A crown-group cnidarian from the Ediacaran of Charnwood Forest, UK |journal=Nature Ecology & Evolution |date=25 July 2022 |volume=6 |issue=8 |pages=1095–1104 |doi=10.1038/s41559-022-01807-x |pmid=35879540 |pmc=9349040 |bibcode=2022NatEE...6.1095D }} [271] => [272] => Some palaeontologists have suggested that animals appeared much earlier than the Cambrian explosion, possibly as early as 1 billion years ago.{{cite book |last1=Campbell |first1=Neil A. |last2=Reece |first2=Jane B. |title=Biology |year=2005 |publisher=Pearson, Benjamin Cummings |isbn=978-0-8053-7171-0 |edition=7th |page=526}} Early fossils that might represent animals appear for example in the 665-million-year-old rocks of the [[Trezona Formation]] of [[South Australia]]. These fossils are interpreted as most probably being early [[Porifera|sponges]].{{cite journal |title=Possible animal-body fossils in pre-Marinoan limestones from South Australia |journal=Nature Geoscience |volume=3 |pages=653–659 |date=17 August 2010 |doi=10.1038/ngeo934 |issue=9 |bibcode=2010NatGe...3..653M |last1=Maloof |first1=Adam C. |last2=Rose |first2=Catherine V. |last3=Beach |first3=Robert |last4=Samuels |first4=Bradley M. |last5=Calmet |first5=Claire C. |last6=Erwin |first6=Douglas H. |last7=Poirier |first7=Gerald R. |last8=Yao |first8=Nan |last9=Simons |first9=Frederik J. }} [273] => [[Trace fossil]]s such as tracks and burrows found in the [[Tonian]] period (from 1 gya) may indicate the presence of [[triploblastic]] worm-like animals, roughly as large (about 5 mm wide) and complex as earthworms.{{cite journal |last1=Seilacher |first1=Adolf |author1-link=Adolf Seilacher |last2=Bose |first2=Pradip K. |last3=Pfluger |first3=Friedrich |title=Triploblastic animals more than 1 billion years ago: trace fossil evidence from india |journal=Science |volume=282 |pages=80–83 |date=2 October 1998 |doi=10.1126/science.282.5386.80 |pmid=9756480 |issue=5386 |bibcode=1998Sci...282...80S}} However, similar tracks are produced by the giant single-celled protist ''[[Gromia sphaerica]]'', so the Tonian trace fossils may not indicate early animal evolution.{{cite journal |last1=Matz |first1=Mikhail V. |last2=Frank |first2=Tamara M. |last3=Marshall |first3=N. Justin |last4=Widder |first4=Edith A. |last5=Johnsen |first5=Sönke |title=Giant Deep-Sea Protist Produces Bilaterian-like Traces |journal=Current Biology |volume=18 |issue=23 |pages=1849–54 |date=9 December 2008 |doi=10.1016/j.cub.2008.10.028 |pmid=19026540 |s2cid=8819675 |doi-access=free }}{{cite news |last=Reilly |first=Michael |title=Single-celled giant upends early evolution |newspaper=NBC News |date=20 November 2008 |url=https://www.nbcnews.com/id/27827279/ |access-date=5 December 2008 |archive-url=https://web.archive.org/web/20130329062924/https://www.nbcnews.com/id/27827279/ |archive-date=29 March 2013 |url-status=live }} Around the same time, the layered mats of [[microorganism]]s called [[stromatolite]]s decreased in diversity, perhaps due to grazing by newly evolved animals.{{Cite encyclopedia |last=Bengtson |first=S. |year=2002 |chapter=Origins and early evolution of predation |encyclopedia=The Paleontological Society Papers |volume=8 |title=The fossil record of predation |editor=Kowalewski, M. |editor2=Kelley, P. H. |pages=289–317 |publisher=[[The Paleontological Society]] |chapter-url=https://www.nrm.se/download/18.4e32c81078a8d9249800021552/Bengtson2002predation.pdf |access-date=3 March 2018 |archive-date=30 October 2019 |archive-url=https://web.archive.org/web/20191030140248/https://www.nrm.se/download/18.4e32c81078a8d9249800021552/Bengtson2002predation.pdf |url-status=live }} Objects such as sediment-filled tubes that resemble trace fossils of the burrows of wormlike animals have been found in 1.2 gya rocks in North America, in 1.5 gya rocks in Australia and North America, and in 1.7 gya rocks in Australia. Their interpretation as having an animal origin is disputed, as they might be water-escape or other structures.{{cite book |last=Seilacher |first=Adolf |author-link=Adolf Seilacher |title=Trace fossil analysis |date=2007 |publisher=Springer |isbn=978-3-540-47226-1 |publication-place=Berlin |pages=176–177 |oclc=191467085}}{{cite journal |last=Breyer |first=J. A. |year=1995 |title=Possible new evidence for the origin of metazoans prior to 1 Ga: Sediment-filled tubes from the Mesoproterozoic Allamoore Formation, Trans-Pecos Texas |journal=[[Geology (journal)|Geology]] |volume=23 |issue=3 |pages=269–272 |doi=10.1130/0091-7613(1995)023<0269:PNEFTO>2.3.CO;2 |bibcode=1995Geo....23..269B }} [274] => [275] => [276] => File:DickinsoniaCostata.jpg|''[[Dickinsonia|Dickinsonia costata]]'' from the [[Ediacaran biota]] (c. 635–542 mya) is one of the earliest animal species known.{{cite journal |last1=Bobrovskiy |first1=Ilya |last2=Hope |first2=Janet M. |last3=Ivantsov |first3=Andrey |last4=Nettersheim |first4=Benjamin J. |last5=Hallmann |first5=Christian |last6=Brocks |first6=Jochen J. |title=Ancient steroids establish the Ediacaran fossil Dickinsonia as one of the earliest animals |journal=Science |volume=361 |issue=6408 |date=20 September 2018 |doi=10.1126/science.aat7228 |pmid=30237355 |pages=1246–1249|bibcode=2018Sci...361.1246B |doi-access=free }} [277] => File:Auroralumina attenboroughii reconstruction.jpg|''[[Auroralumina attenboroughii]]'', an Ediacaran predator (c. 560 mya) [278] => File:20191203 Anomalocaris canadensis.png|''[[Anomalocaris canadensis]]'' is one of the many animal species that emerged in the [[Cambrian explosion]], starting some 539 mya, and found in the fossil beds of the [[Burgess shale]]. [279] => [280] => [281] => == Phylogeny == [282] => [283] => {{further|Lists of animals}} [284] => [285] => === External phylogeny === [286] => [287] => Animals are [[Monophyly|monophyletic]], meaning they are derived from a common ancestor. Animals are the sister group to the [[choanoflagellate]]s, with which they form the [[Choanozoa]].{{cite journal |doi=10.1111/brv.12239 |pmid=26588818 |title=The origin of the animals and a 'Savannah' hypothesis for early bilaterian evolution |journal=[[Biological Reviews]] |volume=92 |issue=1 |pages=446–473 |year=2017 |last1=Budd |first1=Graham E. |last2=Jensen |first2=Sören |doi-access=free }} [288] => The dates on the [[phylogenetic tree]] indicate approximately how many millions of years ago ({{em|mya}}) the lineages split.{{cite journal |last1=Peterson |first1=Kevin J. |last2=Cotton |first2=James A. |last3=Gehling |first3=James G. |last4=Pisani |first4=Davide |date=27 April 2008 |title=The Ediacaran emergence of bilaterians: congruence between the genetic and the geological fossil records |journal=Philosophical Transactions of the Royal Society of London B: Biological Sciences |volume=363 |issue=1496 |pages=1435–1443 |doi=10.1098/rstb.2007.2233 |pmid=18192191 |pmc=2614224 }}{{cite journal |author-link1=Laura Wegener Parfrey |last1=Parfrey |first1=Laura Wegener |last2=Lahr |first2=Daniel J. G. |last3=Knoll |first3=Andrew H. |author-link4=Laura A. Katz |last4=Katz |first4=Laura A. |date=16 August 2011 |title=Estimating the timing of early eukaryotic diversification with multigene molecular clocks |journal=[[Proceedings of the National Academy of Sciences]] |volume=108 |issue=33 |pages=13624–13629 |doi=10.1073/pnas.1110633108 |pmid=21810989 |bibcode=2011PNAS..10813624P |pmc=3158185 |doi-access=free }}{{cite web |title=Raising the Standard in Fossil Calibration |url=https://fossilcalibrations.org/ |website=Fossil Calibration Database |access-date=3 March 2018 |archive-url=https://web.archive.org/web/20180307054141/https://fossilcalibrations.org/ |archive-date=7 March 2018 |url-status=live }}{{Cite journal |last1=Laumer |first1=Christopher E. |last2=Gruber-Vodicka |first2=Harald |last3=Hadfield |first3=Michael G. |last4=Pearse |first4=Vicki B. |last5=Riesgo |first5=Ana |last6=Marioni |first6=John C. |last7=Giribet |first7=Gonzalo |year=2018 |title=Support for a clade of Placozoa and Cnidaria in genes with minimal compositional bias |journal=eLife |volume=2018;7 |pages=e36278 |doi=10.7554/eLife.36278 |pmid=30373720 |pmc=6277202 |doi-access=free }}{{cite journal |last1=Adl |first1=Sina M. |last2=Bass |first2=David |last3=Lane |first3=Christopher E. |last4=Lukeš |first4=Julius |last5=Schoch |first5=Conrad L. |last6=Smirnov |first6=Alexey |last7=Agatha |first7=Sabine |last8=Berney |first8=Cedric |last9=Brown |first9=Matthew W. |date=2018 |title=Revisions to the Classification, Nomenclature, and Diversity of Eukaryotes |journal=Journal of Eukaryotic Microbiology |volume=66 |issue=1 |pages=4–119 |doi=10.1111/jeu.12691|pmid=30257078 |pmc=6492006 }} [289] => [290] => Ros-Rocher and colleagues (2021) trace the origins of animals to unicellular ancestors, providing the external phylogeny shown in the cladogram. Uncertainty of relationships is indicated with dashed lines.{{cite journal | last1=Ros-Rocher | first1=Núria | last2=Pérez-Posada | first2=Alberto | last3=Leger | first3=Michelle M. | last4=Ruiz-Trillo | first4=Iñaki | title=The origin of animals: an ancestral reconstruction of the unicellular-to-multicellular transition | journal=Open Biology | publisher=The Royal Society | volume=11 | issue=2 | year=2021 | page=200359 | issn=2046-2441 | doi=10.1098/rsob.200359| pmid=33622103 | pmc=8061703 }} [291] => [292] => {{Clade |style=font-size:100%; line-height:100% [293] => |label1=[[Opisthokonta]] |sublabel1=1300 mya [294] => |1={{Clade [295] => |1=[[Holomycota]] (inc. fungi) [[File:Asco1013.jpg|60 px]] [296] => |label2=[[Holozoa]] |sublabel2=1100 mya [297] => |2={{Clade |state=dashed [298] => |1=[[Ichthyosporea]] [[File:Abeoforma whisleri-2.jpg|50 px]] [299] => |2=[[Pluriformea]] [[File:Corallochytrium limacisporum.png|50 px]] [300] => |label3=[[Filozoa]] [301] => |3={{Clade [302] => |1=[[Filasterea]] [[File:Ministeria vibrans.jpeg|60 px]] [303] => |label2=[[Choanozoa]] |sublabel2=950 mya [304] => |2={{Clade [305] => |label1=[[Choanoflagellate]]a |1=[[File:Desmarella moniliformis.jpg|60 px]] [306] => |label2 ='''Animalia''' |sublabel2=760 mya |2= [[File:Polychaeta (no) 2.jpg|60 px]] [307] => }} [308] => }} [309] => }} [310] => }} [311] => }} [312] => [313] => === Internal phylogeny === [314] => [315] => The most [[basal animal]]s, the [[Porifera]], [[Ctenophora]], [[Cnidaria]], and [[Placozoa]], have body plans that lack [[Symmetry in biology|bilateral symmetry]]. Their relationships are still disputed; the sister group to all other animals could be the Porifera or the Ctenophora,{{cite journal |last1=Kapli |first1=Paschalia |last2=Telford |first2=Maximilian J. |title=Topology-dependent asymmetry in systematic errors affects phylogenetic placement of Ctenophora and Xenacoelomorpha |journal=Science Advances |date=11 Dec 2020 |volume=6 |issue=10 |pages=eabc5162 |doi=10.1126/sciadv.abc5162 |pmid=33310849 |pmc=7732190 |bibcode=2020SciA....6.5162K |doi-access=free }} both of which lack [[hox gene]]s, which are important for [[Evolutionary developmental biology#Gene toolkit|body plan development]].{{cite journal |last=Giribet |first=Gonzalo |title=Genomics and the animal tree of life: conflicts and future prospects |journal=[[Zoologica Scripta]] |volume=45 |date=27 September 2016 |doi=10.1111/zsc.12215 |pages=14–21 |doi-access=free}} [316] => [317] => Hox genes are found in the Placozoa,{{Cite web |url=https://emb.carnegiescience.edu/sites/emb.carnegiescience.edu/files/evodevo12.pdf |title=Evolution and Development |date=1 May 2012 |website=Carnegie Institution for Science Department of Embryology |page=38 |archive-url=https://web.archive.org/web/20140302084415/https://emb.carnegiescience.edu/sites/emb.carnegiescience.edu/files/evodevo12.pdf |archive-date=2 March 2014 |url-status=dead |access-date=4 March 2018}}{{cite journal |last1=Dellaporta |first1=Stephen |last2=Holland |first2=Peter |last3=Schierwater |first3=Bernd |last4=Jakob |first4=Wolfgang |last5=Sagasser |first5=Sven |last6=Kuhn |first6=Kerstin |title=The Trox-2 Hox/ParaHox gene of Trichoplax (Placozoa) marks an epithelial boundary |journal=Development Genes and Evolution |volume=214 |issue=4 |date=April 2004 |doi=10.1007/s00427-004-0390-8 |pmid=14997392 |pages=170–175| s2cid=41288638 }} Cnidaria,{{cite journal |last1=Finnerty |first1=John |title=Cnidarians Reveal Intermediate Stages in the Evolution of Hox Clusters and Axial Complexity |journal=American Zoologist |date=June 2001 |volume=41 |issue=3 |pages=608-620 |doi=10.1093/icb/41.3.608}} and Bilateria.{{cite journal |doi=10.1046/j.1525-142x.2001.003003170.x |pmid=11440251 |title=Animal phylogeny and the ancestry of bilaterians: Inferences from morphology and 18S rDNA gene sequences |journal=Evolution and Development |volume=3 |issue=3 |pages=170–205 |year=2001 |last1=Peterson |first1=Kevin J. |last2=Eernisse |first2=Douglas J|citeseerx=10.1.1.121.1228 |s2cid=7829548 }}{{cite journal |title=A catalogue of Bilaterian-specific genes – their function and expression profiles in early development |year=2016 |last1=Kraemer-Eis |first1=Andrea |last2=Ferretti |first2=Luca |last3=Schiffer |first3=Philipp |last4=Heger |first4=Peter |last5=Wiehe |first5=Thomas |journal=bioRxiv |doi=10.1101/041806 |s2cid=89080338 |url=https://www.biorxiv.org/content/biorxiv/early/2016/03/19/041806.full.pdf |archive-url=https://web.archive.org/web/20180226032414/https://www.biorxiv.org/content/biorxiv/early/2016/03/19/041806.full.pdf |archive-date=26 February 2018 |url-status=live }} 6,331 groups of [[gene]]s common to all living animals have been identified; these may have arisen from a single [[#Phylogeny|common ancestor]] that lived [[Cryogenian|650 million years ago]] in the [[Precambrian]]. 25 of these are novel core gene groups, found only in animals; of those, 8 are for essential components of the [[Wnt signaling pathway|Wnt]] and [[TGF-beta]] signalling pathways which may have enabled animals to become multicellular by providing a pattern for the body's system of axes (in three dimensions), and another 7 are for [[transcription factor]]s including [[homeodomain]] proteins involved in the [[evo-devo gene toolkit|control of development]].{{cite news |last=Zimmer |first=Carl |author-link=Carl Zimmer |title=The Very First Animal Appeared Amid an Explosion of DNA |url=https://www.nytimes.com/2018/05/04/science/first-animal-genes-evolution.html |date=4 May 2018 |newspaper=[[The New York Times]] |access-date=4 May 2018 |archive-url=https://web.archive.org/web/20180504170120/https://www.nytimes.com/2018/05/04/science/first-animal-genes-evolution.html |archive-date=4 May 2018 |url-status=live }}{{cite journal |last1=Paps |first1=Jordi |last2=Holland |first2=Peter W. H. |title=Reconstruction of the ancestral metazoan genome reveals an increase in genomic novelty |date=30 April 2018 |journal=[[Nature Communications]] |volume=9 |pages=1730 |number=1730 (2018) |doi=10.1038/s41467-018-04136-5 |pmid=29712911 |pmc=5928047 |bibcode=2018NatCo...9.1730P }} [318] => [319] => Giribet and Edgecombe (2020) provide what they consider to be a consensus internal phylogeny of the animals, embodying uncertainty about the structure at the base of the tree (dashed lines).{{cite book |last1=Giribet |first1=G. |last2=Edgecombe |first2=G.D. |title=The Invertebrate Tree of Life |year=2020 |publisher=[[Princeton University Press]] |url={{GBurl|id=YHetDwAAQBAJ|p=21}} |page=21 |isbn=978-0-6911-7025-1 |access-date=27 May 2023 }} [320] => [321] => {{Clade |style = font-size:100%; line-height:100% [322] => |label1='''Animalia''' |sublabel1=''[[Multicellular organism|multicellular]]'' [323] => |1={{Clade [324] => |1=[[Porifera]] [[File:Estonian Museum of Natural History - Sponge.png|60 px]] |state=dashed [325] => |2=[[Ctenophora]] [[File:Mnemiopsis leidyi 247259012.png|60 px]] [326] => |label3=[[ParaHoxozoa]] |sublabel3=''[[hox gene]]s'' [327] => |3={{clade [328] => |1=[[Placozoa]][[File:Trichoplax adhaerens photograph (no background).png|60 px]] |state=dashed [329] => |2=[[Cnidaria]] [[File:Jellyfish, Shaw Ocean Discovery Centre (7201323966).png|70px]] [330] => |label3=[[Bilateria]] |sublabel3=''[[bilateral symmetry|symm.]] embryo'' [331] => |3={{clade [332] => |1=[[Xenacoelomorpha]] [[File:Proporus sp. (no background).png|55 px]] [333] => |label2=[[Nephrozoa]] [334] => |2={{clade [335] => |label1=[[Deuterostomia]] [336] => |1={{clade [337] => |1=[[Ambulacraria]] [[File:Echinaster serpentarius (USNM E28192) 001.png|50 px]] [338] => |2=[[Chordata]] [[File:Cyprin carpi 090613-0329 tdp.png|60 px]] [339] => }} [340] => |label2 =[[Protostomia]] |sublabel2=''[[blastopore]] mouth'' [341] => |2={{clade [342] => |1=[[Ecdysozoa]] [[File:Aptostichus simus Monterey County.jpg|60px]] [343] => |2=[[Spiralia]] [[File:Grapevinesnail 01a.jpg|60px]] [344] => }} [345] => }} [346] => }} [347] => }} [348] => }} [349] => }} [350] => [351] => An alternative phylogeny, from Kapli and colleagues (2021), proposes a clade [[Xenambulacraria]] for the Xenacoelamorpha + Ambulacraria; this is either within Deuterostomia, as sister to Chordata, or the Deuterostomia are recovered as paraphyletic, and Xenambulacraria is sister to the proposed clade [[Centroneuralia]], consisting of Chordata + Protostomia.{{Cite journal |last1=Kapli |first1=Paschalia |last2=Natsidis |first2=Paschalis |last3=Leite |first3=Daniel J. |last4=Fursman |first4=Maximilian |last5=Jeffrie |first5=Nadia |last6=Rahman |first6=Imran A. |last7=Philippe |first7=Hervé |last8=Copley |first8=Richard R. |last9=Telford |first9=Maximilian J. |date=2021-03-19 |title=Lack of support for Deuterostomia prompts reinterpretation of the first Bilateria |journal=Science Advances |volume=7 |issue=12 |pages=eabe2741 |doi=10.1126/sciadv.abe2741 |issn=2375-2548 |pmc=7978419 |pmid=33741592|bibcode=2021SciA....7.2741K }} [352] => [353] => === Non-bilateria === [354] => [355] => [[File:Elephant-ear-sponge.jpg|thumb|upright|Non-bilaterians include sponges (centre) and corals (background).]] [356] => [357] => Several animal phyla lack bilateral symmetry. These are the [[Porifera]] (sea sponges), [[Placozoa]], [[Cnidaria]] (which includes [[jellyfish]], [[sea anemone]]s, and corals), and [[Ctenophora]] (comb jellies). [358] => [359] => Sponges are physically very distinct from other animals, and were long thought to have diverged first, representing the oldest animal phylum and forming a [[sister clade]] to all other animals.{{cite book |last1=Bhamrah |first1=H. S. |last2=Juneja |first2=Kavita |title=An Introduction to Porifera |year=2003 |publisher=Anmol Publications |isbn=978-81-261-0675-2 |page=58}} Despite their morphological dissimilarity with all other animals, genetic evidence suggests sponges may be more closely related to other animals than the comb jellies are.{{Cite journal |last1=Schultz |first1=Darrin T. |last2=Haddock |first2=Steven H. D. |last3=Bredeson |first3=Jessen V. |last4=Green |first4=Richard E. |last5=Simakov |first5=Oleg |last6=Rokhsar |first6=Daniel S. |date=2023-05-17 |title=Ancient gene linkages support ctenophores as sister to other animals |url=https://rdcu.be/dcJSY |journal=Nature |volume=618 |issue=7963 |pages=110–117 |language=en |doi=10.1038/s41586-023-05936-6 |pmid=37198475 |s2cid=258765122 |issn=0028-0836|pmc=10232365 |bibcode=2023Natur.618..110S }}{{Cite journal |last1=Whelan |first1=Nathan V. |last2=Kocot |first2=Kevin M. |last3=Moroz |first3=Tatiana P. |last4=Mukherjee |first4=Krishanu |last5=Williams |first5=Peter |last6=Paulay |first6=Gustav |last7=Moroz |first7=Leonid L. |last8=Halanych |first8=Kenneth M. |date=2017-10-09 |title=Ctenophore relationships and their placement as the sister group to all other animals |url=https://rdcu.be/dcJS3 |journal=Nature Ecology & Evolution |language=en |volume=1 |issue=11 |pages=1737–1746 |doi=10.1038/s41559-017-0331-3 |pmid=28993654 |pmc=5664179 |bibcode=2017NatEE...1.1737W |issn=2397-334X}} Sponges lack the complex organization found in most other animal phyla;{{cite book |last=Sumich |first=James L. |title=Laboratory and Field Investigations in Marine Life |year=2008 |publisher=Jones & Bartlett Learning |isbn=978-0-7637-5730-4 |page=67}} their cells are differentiated, but in most cases not organised into distinct tissues, unlike all other animals.{{cite book |last=Jessop |first=Nancy Meyer |title=Biosphere; a study of life |year=1970 |publisher=[[Prentice-Hall]] |page=428}} They typically feed by drawing in water through pores, filtering out small particles of food.{{cite book |last=Sharma |first=N. S. |title=Continuity And Evolution Of Animals |year=2005 |publisher=Mittal Publications |isbn=978-81-8293-018-6 |page=106}} [360] => [361] => The comb jellies and Cnidaria are radially symmetric and have digestive chambers with a single opening, which serves as both mouth and anus.{{cite book |title=A Living Bay: The Underwater World of Monterey Bay |year=2000 |publisher=University of California Press |isbn=978-0-520-22149-9 |last1=Langstroth |first1=Lovell |last2=Langstroth |first2=Libby |editor-last=Newberry |editor-first=Todd |page=[https://archive.org/details/livingbayunderwa0000lang/page/244 244] |url=https://archive.org/details/livingbayunderwa0000lang/page/244 }} Animals in both phyla have distinct tissues, but these are not organised into discrete [[organ (anatomy)|organs]].{{cite book |last=Safra |first=Jacob E. |title=The New Encyclopædia Britannica, Volume 16 |year=2003 |publisher=Encyclopædia Britannica |isbn=978-0-85229-961-6 |page=523}} They are [[diploblastic]], having only two main germ layers, ectoderm and endoderm.{{cite book |last=Kotpal |first=R.L. |title=Modern Text Book of Zoology: Invertebrates |publisher=Rastogi Publications |isbn=978-81-7133-903-7 |page=184 |year=2012 }} [362] => [363] => The tiny placozoans have no permanent digestive chamber and no symmetry; they superficially resemble amoebae.{{cite book |last=Barnes |first=Robert D. |year=1982 |title=Invertebrate Zoology |publisher=Holt-Saunders International |pages=84–85 |isbn=978-0-03-056747-6}}{{cite web |author= |title=Introduction to Placozoa |url=https://www.ucmp.berkeley.edu/phyla/placozoa/placozoa.html |publisher=UCMP Berkeley |access-date=10 March 2018 |archive-url=https://web.archive.org/web/20180325202849/https://www.ucmp.berkeley.edu/phyla/placozoa/placozoa.html |archive-date=25 March 2018 |url-status=live }} Their phylogeny is poorly defined, and under active research.{{Cite journal |last1=Srivastava |first1=Mansi |last2=Begovic |first2=Emina |last3=Chapman |first3=Jarrod |last4=Putnam |first4=Nicholas H. |last5=Hellsten |first5=Uffe |last6=Kawashima |first6=Takeshi |last7=Kuo |first7=Alan |last8=Mitros |first8=Therese |last9=Salamov |first9=Asaf |last10=Carpenter |first10=Meredith L. |last11=Signorovitch |first11=Ana Y. |last12=Moreno |first12=Maria A. |last13=Kamm |first13=Kai |last14=Grimwood |first14=Jane |last15=Schmutz |first15=Jeremy |date=2008-08-01 |title=The Trichoplax genome and the nature of placozoans |journal=Nature |volume=454 |issue=7207 |pages=955–960 |doi=10.1038/nature07191 |pmid=18719581 |bibcode=2008Natur.454..955S |s2cid=4415492 |issn=0028-0836 |doi-access=free }} [364] => [365] => === Bilateria === [366] => [367] => {{main|Bilateria|Symmetry (biology)#Bilateral symmetry}} [368] => [369] => [[File:Bilaterian body plan.svg|thumb|left|upright=1.35|Idealised [[bilateria]]n body plan.{{efn|Compare [[:File:Annelid redone w white background.svg]] for a more specific and detailed model of a particular phylum with this general body plan.}} With an elongated body and a direction of movement the animal has head and tail ends. Sense organs and mouth form the [[cephalisation|basis of the head]]. Opposed circular and longitudinal muscles enable [[peristalsis|peristaltic motion]].]] [370] => [371] => The remaining animals, the great majority—comprising some 29 phyla and over a million species—form a [[clade]], the Bilateria, which have a bilaterally symmetric [[body plan]]. The Bilateria are [[Triploblasty|triploblastic]], with three well-developed germ layers, and their tissues [[Organogenesis|form distinct organs]]. The digestive chamber has two openings, a mouth and an anus, and there is an internal body cavity, a [[coelom]] or pseudocoelom. These animals have a head end (anterior) and a tail end (posterior), a back (dorsal) surface and a belly (ventral) surface, and a left and a right side. [372] => [373] => Having a front end means that this part of the body encounters stimuli, such as food, favouring [[cephalisation]], the development of a head with [[sense organ]]s and a mouth. Many bilaterians have a combination of circular [[muscle]]s that constrict the body, making it longer, and an opposing set of longitudinal muscles, that shorten the body; these enable soft-bodied animals with a [[hydrostatic skeleton]] to move by [[peristalsis]].{{cite journal |last=Quillin |first=K. J. |title=Ontogenetic scaling of hydrostatic skeletons: geometric, static stress and dynamic stress scaling of the earthworm lumbricus terrestris |journal=[[Journal of Experimental Biology]] |volume=201 |issue=12 |pages=1871–1883 |date=May 1998 |doi=10.1242/jeb.201.12.1871 |pmid=9600869 |url=https://jeb.biologists.org/cgi/pmidlookup?view=long&pmid=9600869 |doi-access=free |access-date=4 March 2018 |archive-date=17 June 2020 |archive-url=https://web.archive.org/web/20200617135617/https://jeb.biologists.org/content/201/12/1871.long |url-status=live }} They also have a gut that extends through the basically cylindrical body from mouth to anus. Many bilaterian phyla have primary [[larva]]e which swim with [[cilia]] and have an apical organ containing sensory cells. However, over evolutionary time, descendant spaces have evolved which have lost one or more of each of these characteristics. For example, adult echinoderms are radially symmetric (unlike their larvae), while some [[Helminths|parasitic worms]] have extremely simplified body structures.{{cite book |last=Minelli |first=Alessandro |title=Perspectives in Animal Phylogeny and Evolution |url={{GBurl|id=jIASDAAAQBAJ|p=53}} |year=2009 |publisher=[[Oxford University Press]] |isbn=978-0-19-856620-5 |page=53}}{{Cite book |url=https://www.sinauer.com/media/wysiwyg/samples/Brusca3e_Chapter_9.pdf |chapter=Introduction to the Bilateria and the Phylum Xenacoelomorpha {{!}} Triploblasty and Bilateral Symmetry Provide New Avenues for Animal Radiation |title=Invertebrates |last=Brusca |first=Richard C. |date=2016 |publisher=[[Sinauer Associates]] |pages=345–372 |isbn=978-1-60535-375-3 |access-date=4 March 2018 |archive-url=https://web.archive.org/web/20190424155137/https://www.sinauer.com/media/wysiwyg/samples/Brusca3e_Chapter_9.pdf |archive-date=24 April 2019 |url-status=live }} [374] => [375] => Genetic studies have considerably changed zoologists' understanding of the relationships within the Bilateria. Most appear to belong to two major lineages, the [[protostomes]] and the [[deuterostomes]].{{cite journal |last=Telford |first=Maximilian J. |title=Resolving Animal Phylogeny: A Sledgehammer for a Tough Nut? |journal=Developmental Cell |volume=14 |issue=4 |year=2008 |doi=10.1016/j.devcel.2008.03.016 |pages=457–459 |pmid=18410719|doi-access=free }} It is often suggested that the basalmost bilaterians are the [[Xenacoelomorpha]], with all other bilaterians belonging to the subclade [[Nephrozoa]]{{cite journal |last1=Philippe |first1=H. |last2=Brinkmann |first2=H. |last3=Copley |first3=R.R. |last4=Moroz |first4=L. L. |last5=Nakano |first5=H. |last6=Poustka |first6=A.J. |last7=Wallberg |first7=A. |last8=Peterson |first8=K. J. |last9=Telford |first9=M.J. |title=Acoelomorph flatworms are deuterostomes related to ''Xenoturbella'' |journal=[[Nature (journal)|Nature]] |volume=470 |pages=255–258 |year=2011 |pmid=21307940 |doi=10.1038/nature09676 |bibcode=2011Natur.470..255P |issue=7333 |pmc=4025995}}{{cite journal |last1=Perseke |first1=M. |last2=Hankeln |first2=T. |last3=Weich |first3=B. |last4=Fritzsch |first4=G. |last5=Stadler |first5=P.F. |last6=Israelsson |first6=O. |last7=Bernhard |first7=D. |last8=Schlegel |first8=M. |title=The mitochondrial DNA of Xenoturbella bocki: genomic architecture and phylogenetic analysis |journal=Theory Biosci |volume=126 |issue=1 |date=August 2007 |pages=35–42 |url=https://www.bioinf.uni-leipzig.de/Publications/PREPRINTS/07-009.pdf |pmid=18087755 |doi=10.1007/s12064-007-0007-7 |citeseerx=10.1.1.177.8060 |s2cid=17065867 |access-date=4 March 2018 |archive-url=https://web.archive.org/web/20190424154927/https://www.bioinf.uni-leipzig.de/Publications/PREPRINTS/07-009.pdf |archive-date=24 April 2019 |url-status=live }}{{cite journal |last1=Cannon |first1=Johanna T. |last2=Vellutini |first2=Bruno C. |last3=Smith III |first3=Julian. |last4=Ronquist |first4=Frederik |last5=Jondelius |first5=Ulf |last6=Hejnol |first6=Andreas |date=3 February 2016 |title=Xenacoelomorpha is the sister group to Nephrozoa |journal=[[Nature (journal)|Nature]] |volume=530 |issue=7588 |pages=89–93 |doi=10.1038/nature16520 |pmid=26842059 |bibcode=2016Natur.530...89C |s2cid=205247296 |url=https://urn.kb.se/resolve?urn=urn:nbn:se:nrm:diva-1844 |access-date=21 February 2022 |archive-date=30 July 2022 |archive-url=https://web.archive.org/web/20220730091447/http://nrm.diva-portal.org/smash/record.jsf?pid=diva2%3A1037430&dswid=-7165 |url-status=live }} However, this suggestion has been contested, with other studies finding that xenacoelomorphs are more closely related to Ambulacraria than to other bilaterians. [376] => {{clear}} [377] => [378] => ==== Protostomes and deuterostomes ==== [379] => [380] => {{further|Embryological origins of the mouth and anus}} [381] => [382] => {{main|Protostome|Deuterostome}} [383] => [384] => [[File:Protovsdeuterostomes.svg|thumb|The bilaterian gut develops in two ways. In many [[protostome]]s, the blastopore develops into the mouth, while in [[deuterostome]]s it becomes the anus.]] [385] => [386] => Protostomes and deuterostomes differ in several ways. Early in development, deuterostome embryos undergo radial [[Cleavage (embryo)|cleavage]] during cell division, while many protostomes (the [[Spiralia]]) undergo spiral cleavage.{{cite journal |last=Valentine |first=James W. |date=July 1997 |title=Cleavage patterns and the topology of the metazoan tree of life |journal=PNAS |volume=94 |pages=8001–8005 |bibcode=1997PNAS...94.8001V |doi=10.1073/pnas.94.15.8001 |pmid=9223303 |pmc=21545 |issue=15|doi-access=free }} [387] => Animals from both groups possess a complete digestive tract, but in protostomes the first opening of the [[archenteron|embryonic gut]] develops into the mouth, and the anus forms secondarily. In deuterostomes, the anus forms first while the mouth develops secondarily.{{cite book |last1=Peters |first1=Kenneth E. |last2=Walters |first2=Clifford C. |last3=Moldowan |first3=J. Michael |title=The Biomarker Guide: Biomarkers and isotopes in petroleum systems and Earth history |volume=2 |year=2005 |publisher=Cambridge University Press |isbn=978-0-521-83762-0 |page=717}}{{cite book |last1=Hejnol |first1=A. |last2=Martindale |first2=M.Q. |url=https://www.researchgate.net/publication/230766195 |chapter=The mouth, the anus, and the blastopore – open questions about questionable openings |title=Animal Evolution – Genomes, Fossils, and Trees |editor1=Telford, M.J. |editor2=Littlewood, D.J. |date=2009 |publisher=Oxford University Press |isbn=978-0-19-957030-0 |pages=33–40 |access-date=1 March 2018 |archive-url=https://web.archive.org/web/20181028190247/https://www.researchgate.net/publication/230766195 |archive-date=28 October 2018 |url-status=live }} Most protostomes have [[Schizocoely|schizocoelous development]], where cells simply fill in the interior of the gastrula to form the mesoderm. In deuterostomes, the mesoderm forms by [[Enterocoely|enterocoelic pouching]], through invagination of the endoderm.{{cite book |last=Safra |first=Jacob E. |title=The New Encyclopædia Britannica, Volume 1; Volume 3 |year=2003 |publisher=Encyclopædia Britannica |isbn=978-0-85229-961-6 |page=767}} [388] => [389] => The main deuterostome phyla are the Echinodermata and the Chordata.{{cite book |last=Hyde |first=Kenneth |title=Zoology: An Inside View of Animals |year=2004 |publisher=[[Kendall Hunt]] |isbn=978-0-7575-0997-1 |page=345}} Echinoderms are exclusively marine and include [[starfish]], [[sea urchin]]s, and [[sea cucumber]]s.{{cite book |last=Alcamo |first=Edward |title=Biology Coloring Workbook |year=1998 |publisher=[[The Princeton Review]] |isbn=978-0-679-77884-4 |page=220}} The chordates are dominated by the [[vertebrates]] (animals with [[Vertebral column|backbones]]),{{cite book |last=Holmes |first=Thom |title=The First Vertebrates |publisher=Infobase Publishing |year=2008 |isbn=978-0-8160-5958-4 |page=64}} which consist of [[fish]]es, [[amphibia]]ns, [[reptile]]s, [[bird]]s, and [[mammal]]s.{{cite book |last=Rice |first=Stanley A. |title=Encyclopedia of evolution |publisher=Infobase Publishing |year=2007 |page=[https://archive.org/details/encyclopediaofev0000rice/page/75 75] |isbn=978-0-8160-5515-9 |url=https://archive.org/details/encyclopediaofev0000rice/page/75 }} The deuterostomes also include the [[Hemichordata]] (acorn worms).{{cite book |last1=Tobin |first1=Allan J. |last2=Dusheck |first2=Jennie |title=Asking about life |year=2005 |publisher=Cengage Learning |isbn=978-0-534-40653-0 |page=497}}{{cite journal |title=Hemichordate genomes and deuterostome origins |journal=[[Nature (journal)|Nature]] |date=26 November 2015 |pages=459–465 |volume=527 |issue=7579 |doi=10.1038/nature16150 |first1=Oleg |last1=Simakov |first2=Takeshi |last2=Kawashima |first3=Ferdinand |last3=Marlétaz |first4=Jerry |last4=Jenkins |first5=Ryo |last5=Koyanagi |first6=Therese |last6=Mitros |first7=Kanako |last7=Hisata |first8=Jessen |last8=Bredeson |first9=Eiichi |last9=Shoguchi |pmid=26580012 |pmc=4729200 |bibcode=2015Natur.527..459S }} [390] => [391] => ===== Ecdysozoa ===== [392] => [393] => {{main|Ecdysozoa}} [394] => [395] => [[File:Anax Imperator 2(loz).JPG|thumb|left|upright|[[Ecdysis]]: a [[dragonfly]] has emerged from its dry [[exuviae]] and is expanding its wings. Like other [[arthropods]], its body is [[Segmentation (biology)|divided into segments]].]] [396] => [397] => The Ecdysozoa are protostomes, named after their shared [[Phenotypic trait|trait]] of [[ecdysis]], growth by moulting.{{cite book |last=Dawkins |first=Richard |author-link=Richard Dawkins |title=The Ancestor's Tale: A Pilgrimage to the Dawn of Evolution |year=2005 |publisher=[[Houghton Mifflin Harcourt]] |isbn=978-0-618-61916-0 |page=[https://archive.org/details/ancestorstale00rich_0/page/381 381] |url=https://archive.org/details/ancestorstale00rich_0/page/381 }} They include the largest animal phylum, the [[Arthropod|Arthropoda]], which contains insects, spiders, crabs, and their kin. All of these have a body divided into [[Segmentation (biology)|repeating segments]], typically with paired appendages. Two smaller phyla, the [[Onychophora]] and [[Tardigrada]], are close relatives of the arthropods and share these traits. The ecdysozoans also include the Nematoda or roundworms, perhaps the second largest animal phylum. Roundworms are typically microscopic, and occur in nearly every environment where there is water;{{cite book |last1=Prewitt |first1=Nancy L. |last2=Underwood |first2=Larry S. |last3=Surver |first3=William |title=BioInquiry: making connections in biology |year=2003 |publisher=John Wiley |isbn=978-0-471-20228-8 |page=[https://archive.org/details/bioinquiry00nanc_0/page/289 289] |url=https://archive.org/details/bioinquiry00nanc_0/page/289 }} some are important parasites.{{cite book |title=Parasites in social insects |year=1998 |publisher=[[Princeton University Press]] |isbn=978-0-691-05924-2 |last=Schmid-Hempel |first=Paul |page=75}} Smaller phyla related to them are the [[Nematomorpha]] or horsehair worms, and the [[Kinorhyncha]], [[Priapulida]], and [[Loricifera]]. These groups have a reduced coelom, called a pseudocoelom.{{cite book |last1=Miller |first1=Stephen A. |last2=Harley |first2=John P. |title=Zoology |url={{GBurl|id=BWZFAQAAIAAJ}} |year=2006 |publisher=[[McGraw-Hill]] |page=173 |isbn=978-0-07-063682-8}} [398] => [399] => ===== Spiralia ===== [400] => [401] => {{main|Spiralia}} [402] => [403] => [[File:Spiral cleavage in Trochus.png|thumb|upright=1.5|[[Spiral cleavage]] in a sea snail embryo]] [404] => [405] => The Spiralia are a large group of protostomes that develop by spiral cleavage in the early embryo.{{cite journal |pmid=10781038 |pmc=34316 |jstor=122407 |bibcode=2000PNAS...97.4434S |doi=10.1073/pnas.97.9.4434 |title=Evolution of the bilaterian body plan: What have we learned from annelids? |journal=Proceedings of the National Academy of Sciences |volume=97 |issue=9 |pages=4434–4437 |year=2000|last1=Shankland |first1=M. |last2=Seaver |first2=E.C. |doi-access=free }} The Spiralia's phylogeny has been disputed, but it contains a large clade, the superphylum [[Lophotrochozoa]], and smaller groups of phyla such as the [[Rouphozoa]] which includes the [[gastrotrich]]s and the [[flatworm]]s. All of these are grouped as the [[Platytrochozoa]], which has a sister group, the [[Gnathifera (clade)|Gnathifera]], which includes the [[rotifer]]s.{{cite journal |last1=Struck |first1=Torsten H. |last2=Wey-Fabrizius |first2=Alexandra R. |last3=Golombek |first3=Anja |last4=Hering |first4=Lars |last5=Weigert |first5=Anne |last6=Bleidorn |first6=Christoph |last7=Klebow |first7=Sabrina |last8=Iakovenko |first8=Nataliia |last9=Hausdorf |first9=Bernhard |last10=Petersen |first10=Malte |last11=Kück |first11=Patrick |last12=Herlyn |first12=Holger |last13=Hankeln |first13=Thomas |title=Platyzoan Paraphyly Based on Phylogenomic Data Supports a Noncoelomate Ancestry of Spiralia |journal=Molecular Biology and Evolution |volume=31 |issue=7 |date=2014 |doi=10.1093/molbev/msu143 |pages=1833–1849 |pmid=24748651| doi-access=free }}{{Cite journal |last1=Fröbius |first1=Andreas C. |last2=Funch |first2=Peter |date=April 2017 |title=Rotiferan Hox genes give new insights into the evolution of metazoan bodyplans |journal=Nature Communications |volume=8 |issue=1 |pages=9 |doi=10.1038/s41467-017-00020-w |pmid=28377584 |pmc=5431905 |bibcode=2017NatCo...8....9F }} [406] => [407] => The Lophotrochozoa includes the [[mollusc]]s, [[annelid]]s, [[brachiopod]]s, [[nemertea]]ns, [[bryozoa]] and [[Entoprocta|entoprocts]].{{cite journal| last1=Hervé |first1=Philippe |last2=Lartillot |first2=Nicolas |last3=Brinkmann |first3=Henner |date=May 2005 |title=Multigene Analyses of Bilaterian Animals Corroborate the Monophyly of Ecdysozoa, Lophotrochozoa, and Protostomia |journal=Molecular Biology and Evolution |volume=22 |issue=5| pages=1246–1253 |doi=10.1093/molbev/msi111 |pmid=15703236| doi-access=free }}{{cite web |title=Introduction to the Lophotrochozoa {{!}} Of molluscs, worms, and lophophores... |url=https://www.ucmp.berkeley.edu/phyla/lophotrochozoa.html |publisher=UCMP Berkeley |access-date=28 February 2018 |archive-url=https://web.archive.org/web/20000816183847/https://www.ucmp.berkeley.edu/phyla/lophotrochozoa.html |archive-date=16 August 2000 |url-status=dead |last=Speer |first=Brian R. |date=2000 }} The molluscs, the second-largest animal phylum by number of described species, includes [[snail]]s, [[clam]]s, and [[squid]]s, while the annelids are the segmented worms, such as [[earthworm]]s, [[lugworm]]s, and [[leech]]es. These two groups have long been considered close relatives because they share [[trochophore]] larvae.{{cite journal |last1=Giribet |first1=G. |last2=Distel |first2=D.L. |last3=Polz |first3=M. |last4=Sterrer |first4=W. |last5=Wheeler |first5=W.C. |year=2000 |title=Triploblastic relationships with emphasis on the acoelomates and the position of Gnathostomulida, Cycliophora, Plathelminthes, and Chaetognatha: a combined approach of 18S rDNA sequences and morphology |journal=Syst Biol |volume=49 |issue=3 |pages=539–562 |doi=10.1080/10635159950127385 |pmid=12116426|doi-access=free }}{{cite journal |title=Phylogenetic Relationships of Annelids, Molluscs, and Arthropods Evidenced from Molecules and Morphology |journal=[[Journal of Molecular Evolution]] |volume=43 |issue=3 |pages=207–215 |date=September 1996 |doi=10.1007/PL00006079 |pmid=8703086 |last1=Kim |first1=Chang Bae |last2=Moon |first2=Seung Yeo |last3=Gelder |first3=Stuart R. |last4=Kim |first4=Won|bibcode=1996JMolE..43..207K }} [408] => [409] => == History of classification == [410] => [411] => {{further|Taxonomy (biology)|History of zoology through 1859|History of zoology since 1859}} [412] => [413] => [[File:Jean-Baptiste de Lamarck.jpg|thumb|upright|[[Jean-Baptiste de Lamarck]] led the creation of a modern classification of [[invertebrates]], breaking up Linnaeus's "Vermes" into 9 phyla by 1809.]] [414] => [415] => In the [[classical era]], Aristotle [[Aristotle's biology|divided animals]],{{efn|In his ''[[History of Animals]]'' and ''[[Parts of Animals]]''.}} based on his own observations, into those with blood (roughly, the vertebrates) and those without. The animals were then [[Scala naturae|arranged on a scale]] from man (with blood, 2 legs, rational soul) down through the live-bearing tetrapods (with blood, 4 legs, sensitive soul) and other groups such as crustaceans (no blood, many legs, sensitive soul) down to spontaneously generating creatures like sponges (no blood, no legs, vegetable soul). [[Aristotle]] was uncertain whether sponges were animals, which in his system ought to have sensation, appetite, and locomotion, or plants, which did not: he knew that sponges could sense touch, and would contract if about to be pulled off their rocks, but that they were rooted like plants and never moved about.{{cite book |last=Leroi |first=Armand Marie |author-link=Armand Marie Leroi |title=The Lagoon: How Aristotle Invented Science |title-link=Aristotle's Lagoon |publisher=Bloomsbury |date=2014 |isbn=978-1-4088-3622-4 |pages=111–119, 270–271}} [416] => [417] => In 1758, [[Carl Linnaeus]] created the first [[hierarchical]] classification in his ''[[Systema Naturae]]''.{{cite book |last=Linnaeus |first=Carl |author-link=Carl Linnaeus |title=Systema naturae per regna tria naturae :secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. |edition=[[10th edition of Systema Naturae|10th]] |publisher=Holmiae (Laurentii Salvii) |year=1758 |url=https://www.biodiversitylibrary.org/bibliography/542 |access-date=22 September 2008 |language=la |archive-url=https://web.archive.org/web/20081010032456/https://www.biodiversitylibrary.org/bibliography/542 |archive-date=10 October 2008 |url-status=live}} In his original scheme, the animals were one of three kingdoms, divided into the classes of [[Vermes in the 10th edition of Systema Naturae|Vermes]], [[Insecta in the 10th edition of Systema Naturae|Insecta]], [[Pisces in the 10th edition of Systema Naturae|Pisces]], [[Amphibia in the 10th edition of Systema Naturae|Amphibia]], [[Aves in the 10th edition of Systema Naturae|Aves]], and [[Mammalia in the 10th edition of Systema Naturae|Mammalia]]. Since then the last four have all been subsumed into a single phylum, the [[chordate|Chordata]], while his Insecta (which included the crustaceans and arachnids) and Vermes have been renamed or broken up. The process was begun in 1793 by [[Jean-Baptiste de Lamarck]], who called the Vermes ''une espèce de chaos'' (a chaotic mess){{efn|The French prefix ''une espèce de'' is pejorative.{{cite web |title=Espèce de |url=https://dictionnaire.reverso.net/francais-anglais/esp%C3%A8ce%20de%20cr%C3%A9tin |publisher=Reverso Dictionnnaire |access-date=1 March 2018 |archive-url=https://web.archive.org/web/20130728151210/https://dictionnaire.reverso.net/francais-anglais/esp%C3%A8ce%20de%20cr%C3%A9tin |archive-date=28 July 2013 |url-status=live }}}} and split the group into three new phyla: worms, echinoderms, and polyps (which contained corals and jellyfish). By 1809, in his ''[[Philosophie Zoologique]]'', Lamarck had created 9 phyla apart from vertebrates (where he still had 4 phyla: mammals, birds, reptiles, and fish) and molluscs, namely [[cirripede]]s, annelids, crustaceans, arachnids, insects, worms, [[Radiata|radiates]], polyps, and [[infusoria]]ns.{{cite book |last=Gould |first=Stephen Jay |author-link=Stephen Jay Gould |title=The Lying Stones of Marrakech |url={{GBurl|id=wApMpVmi-5gC|p=130}} |year=2011 |publisher=Harvard University Press |isbn=978-0-674-06167-5 |pages=130–134}} [418] => [419] => In his 1817 ''[[Le Règne Animal]]'', [[Georges Cuvier]] used [[comparative anatomy]] to group the animals into four ''embranchements'' ("branches" with different body plans, roughly corresponding to phyla), namely vertebrates, molluscs, articulated animals (arthropods and annelids), and [[zoophytes|zoophytes (radiata)]] (echinoderms, cnidaria and other forms).{{cite book |last=De Wit |first=Hendrik C. D. |title=Histoire du Développement de la Biologie, Volume III |publisher=Presses Polytechniques et Universitaires Romandes |date=1994 |pages=94–96 |isbn=978-2-88074-264-5}} This division into four was followed by the embryologist [[Karl Ernst von Baer]] in 1828, the zoologist [[Louis Agassiz]] in 1857, and the comparative anatomist [[Richard Owen]] in 1860. [420] => [421] => In 1874, [[Ernst Haeckel]] divided the animal kingdom into two subkingdoms: Metazoa (multicellular animals, with five phyla: coelenterates, echinoderms, articulates, molluscs, and vertebrates) and Protozoa (single-celled animals), including a sixth animal phylum, sponges.{{cite book |last1=Haeckel |first1=Ernst |author-link=Ernst Haeckel |title=Anthropogenie oder Entwickelungsgeschichte des menschen |url=https://archive.org/details/anthropogenieod05haecgoog |year=1874 |page=202 |language=de|publisher=W. Engelmann }}{{cite book |last=Valentine |first=James W. |title=On the Origin of Phyla |url={{GBurl|id=DMBkmHm5fe4C|p=8}} |year=2004 |publisher=University of Chicago Press |isbn=978-0-226-84548-7 |pages=7–8}} The protozoa were later moved to the former kingdom [[Protista]], leaving only the Metazoa as a synonym of Animalia.{{cite book |last1=Hutchins |first1=Michael |title=Grzimek's Animal Life Encyclopedia |url=https://archive.org/details/animallifeprotos02mich_714 |url-access=limited |year=2003 |edition=2nd |publisher=Gale |isbn=978-0-7876-5777-2 |page=[https://archive.org/details/animallifeprotos02mich_714/page/n21 3]}} [422] => [423] => == In human culture == [424] => [425] => === Practical uses === [426] => [427] => {{main|Animals in culture}} [428] => [429] => [[File:Carni bovine macellate.JPG|thumb|upright|left|Sides of [[beef]] in a [[slaughterhouse]]]] [430] => [431] => The human population exploits a large number of other animal species for food, both of [[domestication of animals|domesticated]] livestock species in [[animal husbandry]] and, mainly at sea, by hunting wild species.{{cite web |url=https://www.fao.org/fishery/ |title=Fisheries and Aquaculture |publisher=[[Food and Agriculture Organization]] |access-date=8 July 2016 |archive-url=https://web.archive.org/web/20090519173740/https://www.fao.org/fishery |archive-date=19 May 2009 |url-status=live }} Marine fish of many species are [[fishing|caught commercially]] for food. A smaller number of species are [[fish farming|farmed commercially]].{{cite book |last=Helfman |first=Gene S. |title=Fish Conservation: A Guide to Understanding and Restoring Global Aquatic Biodiversity and Fishery Resources |url=https://archive.org/details/fishconservation00helf |url-access=limited |date=2007 |publisher=Island Press |isbn=978-1-59726-760-1 |page=[https://archive.org/details/fishconservation00helf/page/n25 11]}}{{cite web |title=World Review of Fisheries and Aquaculture |url=https://www.fao.org/docrep/016/i2727e/i2727e01.pdf |publisher=FAO |access-date=13 August 2015 |archive-url=https://web.archive.org/web/20150828131307/https://www.fao.org/docrep/016/i2727e/i2727e01.pdf |archive-date=28 August 2015 |url-status=live }} Humans and their [[livestock]] make up more than 90% of the biomass of all terrestrial vertebrates, and almost as much as all insects combined.{{cite journal |last=Eggleton |first=Paul |title=The State of the World's Insects |journal=Annual Review of Environment and Resources |date=17 October 2020 |volume=45 |issue=1 |pages=61–82 |doi=10.1146/annurev-environ-012420-050035 |issn=1543-5938 |doi-access=free}} [432] => [433] => [[Invertebrates]] including [[cephalopod]]s, [[crustacea]]ns, and [[bivalve]] or [[gastropod]] molluscs are hunted or farmed for food.{{cite journal |title=Shellfish climbs up the popularity ladder |journal=Seafood Business |url=https://www.highbeam.com/doc/1G1-85675992.html |archive-url=https://web.archive.org/web/20121105143157/https://www.highbeam.com/doc/1G1-85675992.html |url-status=dead |archive-date=2012-11-05 |access-date=8 July 2016 |date=January 2002 }} [[Chicken]]s, [[cattle]], [[sheep]], [[pig]]s, and other animals are raised as livestock for meat across the world.{{cite news |title=Graphic detail Charts, maps and infographics. Counting chickens |newspaper=The Economist |url=https://www.economist.com/blogs/dailychart/2011/07/global-livestock-counts |access-date=23 June 2016 |date=27 July 2011 |archive-url=https://web.archive.org/web/20160715181213/https://www.economist.com/blogs/dailychart/2011/07/global-livestock-counts |archive-date=15 July 2016 |url-status=live }}{{cite web |url=https://cattle-today.com/ |title=Breeds of Cattle at Cattle Today |publisher=Cattle-today.com |access-date=15 October 2013 |archive-url=https://web.archive.org/web/20110715234745/https://cattle-today.com/ |archive-date=15 July 2011 |url-status=live }}{{cite web |last1=Lukefahr |first1=S. D. |last2=Cheeke |first2=P. R. |title=Rabbit project development strategies in subsistence farming systems |url=https://www.fao.org/docrep/U4900T/u4900T0m.htm |publisher=[[Food and Agriculture Organization]] |access-date=23 June 2016 |archive-url=https://web.archive.org/web/20160506105314/https://www.fao.org/docrep/U4900T/u4900T0m.htm |archive-date=6 May 2016 |url-status=live }} Animal fibres such as wool are used to make textiles, while animal [[sinew]]s have been used as lashings and bindings, and leather is widely used to make shoes and other items. Animals have been hunted and farmed for their fur to make items such as coats and hats.{{cite web |title=Ancient fabrics, high-tech geotextiles |url=https://www.naturalfibres2009.org/en/fibres/ |publisher=Natural Fibres |access-date=8 July 2016 |archive-url=https://web.archive.org/web/20160720093749/https://www.naturalfibres2009.org/en/fibres/ |archive-date=20 July 2016 |url-status=dead }} Dyestuffs including [[carmine]] ([[cochineal]]),{{cite book |url=https://www.fao.org/docrep/v8879e/v8879e09.htm |chapter=Cochineal and Carmine |title=Major colourants and dyestuffs, mainly produced in horticultural systems |publisher=FAO |access-date=16 June 2015 |archive-url=https://web.archive.org/web/20180306060330/https://www.fao.org/docrep/v8879e/V8879e09.htm |archive-date=6 March 2018 |url-status=live }}{{cite web |url=https://www.fda.gov/ForIndustry/ColorAdditives/GuidanceComplianceRegulatoryInformation/ucm153038.htm |title=Guidance for Industry: Cochineal Extract and Carmine |publisher=FDA |access-date=6 July 2016 |archive-url=https://web.archive.org/web/20160713100106/https://www.fda.gov/ForIndustry/ColorAdditives/GuidanceComplianceRegulatoryInformation/ucm153038.htm |archive-date=13 July 2016 |url-status=live }} [[shellac]],{{cite news |title=How Shellac Is Manufactured |url=https://nla.gov.au/nla.news-article55073762 |access-date=17 July 2015 |newspaper=The Mail (Adelaide, SA : 1912–1954) |date=18 December 1937 |archive-date=30 July 2022 |archive-url=https://web.archive.org/web/20220730091433/https://trove.nla.gov.au/newspaper/article/55073762 |url-status=live }}{{cite journal |last1=Pearnchob |first1=N. |last2=Siepmann |first2=J. |author3=Bodmeier, R. |year=2003 |title=Pharmaceutical applications of shellac: moisture-protective and taste-masking coatings and extended-release matrix tablets |journal=Drug Development and Industrial Pharmacy |volume=29 |issue=8 |pages=925–938 |pmid=14570313 |doi=10.1081/ddc-120024188|s2cid=13150932 }} and [[Kermes (dye)|kermes]]{{cite book |last=Barber |first=E. J. W. |title=Prehistoric Textiles |year=1991 |publisher=Princeton University Press |isbn=978-0-691-00224-8 |pages=230–231}}{{cite book |last=Munro |first=John H. |title=The Cambridge History of Western Textiles |chapter=Medieval Woollens: Textiles, Technology, and Organisation |editor-last1=Jenkins | editor-first1=David |year=2003 |publisher=Cambridge University Press |isbn=978-0-521-34107-3 |pages=214–215}} have been made from the bodies of insects. [[Working animals]] including cattle and horses have been used for work and transport from the first days of agriculture.{{cite book |last=Pond |first=Wilson G. |title=Encyclopedia of Animal Science |url={{GBurl|id=1SQl7Ao3mHoC|p=248}} |year=2004 |publisher=CRC Press |isbn=978-0-8247-5496-9 |pages=248–250 |access-date=22 February 2018 }} [434] => [435] => Animals such as the fruit fly ''[[Drosophila melanogaster]]'' serve a major role in science as [[model organism|experimental models]].{{cite web |title=Genetics Research |url=https://www.aht.org.uk/cms-display/genetics.html |publisher=Animal Health Trust |access-date=24 June 2016 |archive-url=https://web.archive.org/web/20171212193051/https://www.aht.org.uk/cms-display/genetics.html |archive-date=12 December 2017 |url-status=dead }}{{cite web |title=Drug Development |url=https://www.animalresearch.info/en/drug-development/ |publisher=Animal Research.info |access-date=24 June 2016 |archive-url=https://web.archive.org/web/20160608124406/https://www.animalresearch.info/en/drug-development/ |archive-date=8 June 2016 |url-status=live }}{{cite web |title=Animal Experimentation |url=https://www.bbc.co.uk/ethics/animals/using/experiments_1.shtml |publisher=BBC |access-date=8 July 2016 |archive-url=https://web.archive.org/web/20160701220536/https://www.bbc.co.uk/ethics/animals/using/experiments_1.shtml |archive-date=1 July 2016 |url-status=live }}{{cite web |title=EU statistics show decline in animal research numbers |url=https://speakingofresearch.com/2013/12/12/eu-statistics-show-decline-in-animal-research-numbers/ |publisher=Speaking of Research |year=2013 |access-date=24 January 2016 |archive-url=https://web.archive.org/web/20171006162448/https://speakingofresearch.com/2013/12/12/eu-statistics-show-decline-in-animal-research-numbers/ |archive-date=6 October 2017 |url-status=live }} Animals have been used to create [[vaccine]]s since their discovery in the 18th century.{{cite web |title=Vaccines and animal cell technology |date=10 June 2013 |url=https://www.actip.org/library/vaccines-and-animal-cell-technology/ |publisher=Animal Cell Technology Industrial Platform |access-date=9 July 2016 |archive-url=https://web.archive.org/web/20160713184805/https://www.actip.org/library/vaccines-and-animal-cell-technology/ |archive-date=13 July 2016 |url-status=live }} Some medicines such as the cancer drug [[trabectedin]] are based on [[toxin]]s or other molecules of animal origin.{{cite web |title=Medicines by Design |url=https://publications.nigms.nih.gov/medbydesign/chapter3.html |publisher=National Institute of Health |access-date=9 July 2016 |archive-url=https://web.archive.org/web/20160604214644/https://publications.nigms.nih.gov/medbydesign/chapter3.html |archive-date=4 June 2016 |url-status=live }} [436] => [437] => [[File:Hebbuz.JPG|thumb|A [[gun dog]] retrieving a duck during a hunt]] [438] => [439] => People have used [[hunting dog]]s to help chase down and retrieve animals,{{cite book |last=Fergus |first=Charles |title=Gun Dog Breeds, A Guide to Spaniels, Retrievers, and Pointing Dogs |publisher=The Lyons Press |date=2002 |isbn=978-1-58574-618-7}} and [[Bird of prey|birds of prey]] to catch birds and mammals,{{cite web |title=History of Falconry |url=https://www.thefalconrycentre.co.uk/bird-info/conservation/nocturnal-raptors/history-falconry/ |publisher=The Falconry Centre |access-date=22 April 2016 |archive-url=https://web.archive.org/web/20160529023926/https://thefalconrycentre.co.uk/bird-info/conservation/nocturnal-raptors/history-falconry/ |archive-date=29 May 2016 |url-status=live }} while tethered [[cormorant]]s have been [[Cormorant fishing|used to catch fish]].{{cite book |last=King |first=Richard J. |title=The Devil's Cormorant: A Natural History |url={{GBurl|id=ucGyAAAAQBAJ|p=9}} |date=2013 |publisher=University of New Hampshire Press |isbn=978-1-61168-225-0 |page=9}} [[Poison dart frog]]s have been used to poison the tips of [[blowdart|blowpipe darts]].{{cite web |url=https://amphibiaweb.org/lists/Dendrobatidae.shtml |title=AmphibiaWeb – Dendrobatidae |publisher=AmphibiaWeb |access-date=2008-10-10 |archive-url=https://web.archive.org/web/20110810090554/https://amphibiaweb.org/lists/Dendrobatidae.shtml |archive-date=10 August 2011 |url-status=live }}{{cite web |url=https://animaldiversity.ummz.umich.edu/site/accounts/information/Dendrobatidae.html |title=Dendrobatidae |access-date=9 July 2016 |last=Heying |first=H. |year=2003 |publisher=Animal Diversity Web |archive-url=https://web.archive.org/web/20110212005358/https://animaldiversity.ummz.umich.edu/site/accounts/information/Dendrobatidae.html |archive-date=12 February 2011 |url-status=live }} [440] => A wide variety of animals are kept as pets, from invertebrates such as tarantulas, octopuses, and [[praying mantis]]es,{{cite web |title=Other bugs |date=18 February 2011 |url=https://www.keepinginsects.com/cockroaches-locusts-ants/ |publisher=Keeping Insects |access-date=8 July 2016 |archive-url=https://web.archive.org/web/20160707170022/https://www.keepinginsects.com/cockroaches-locusts-ants/ |archive-date=7 July 2016 |url-status=live }} reptiles such as [[snake]]s and [[chameleon]]s,{{cite web |last=Kaplan |first=Melissa |title=So, you think you want a reptile? |url=https://www.anapsid.org/parent.html |publisher=Anapsid.org |access-date=8 July 2016 |archive-url=https://web.archive.org/web/20160703115141/https://www.anapsid.org/parent.html |archive-date=3 July 2016 |url-status=live }} and birds including [[Domestic canary|canaries]], [[parakeet]]s, and [[parrot]]s{{cite web |title=Pet Birds |url=https://www.humanesociety.org/animals/pet_birds/ |publisher=PDSA |access-date=8 July 2016 |archive-url=https://web.archive.org/web/20160707053516/https://www.humanesociety.org/animals/pet_birds/ |archive-date=7 July 2016 |url-status=live }} all finding a place. However, the most kept pet species are mammals, namely [[dog]]s, [[cat]]s, and [[rabbit]]s.{{cite web |url=https://www.shea-online.org/Portals/0/PDFs/Animals%20in%20Healthcare%20Facilities.pdf |title=Animals in Healthcare Facilities |year=2012 |url-status=dead |archive-url=https://web.archive.org/web/20160304102728/https://www.shea-online.org/Portals/0/PDFs/Animals%20in%20Healthcare%20Facilities.pdf |archive-date=4 March 2016 }}{{cite web |last=The Humane Society of the United States |title=U.S. Pet Ownership Statistics |url=https://www.humanesociety.org/issues/pet_overpopulation/facts/pet_ownership_statistics.html |access-date=27 April 2012 |archive-url=https://web.archive.org/web/20120407193941/https://www.humanesociety.org/issues/pet_overpopulation/facts/pet_ownership_statistics.html |archive-date=7 April 2012 |url-status=live }}{{cite web |title=U.S. Rabbit Industry profile |publisher=[[United States Department of Agriculture]] |url=https://www.aphis.usda.gov/animal_health/emergingissues/downloads/RabbitReport1.pdf |access-date=10 July 2013 |url-status=dead |archive-url=https://web.archive.org/web/20131020161216/https://www.aphis.usda.gov/animal_health/emergingissues/downloads/RabbitReport1.pdf |archive-date=20 October 2013 }} There is a tension between the role of animals as companions to humans, and their existence as [[animal rights|individuals with rights]] of their own.{{cite journal |last=Plous |first=S. |title=The Role of Animals in Human Society |date=1993 |doi=10.1111/j.1540-4560.1993.tb00906.x |journal=Journal of Social Issues |volume=49 |issue=1 |pages=1–9}} [441] => A wide variety of terrestrial and aquatic animals are hunted [[Animals in sport|for sport]].{{cite book |last=Hummel |first=Richard |title=Hunting and Fishing for Sport: Commerce, Controversy, Popular Culture |date=1994 |publisher=Popular Press |isbn=978-0-87972-646-1 |url-access=registration |url=https://archive.org/details/huntingfishingfo0000humm }} [442] => [443] => === Symbolic uses === [444] => [445] => [[File:Alexander Coosemans - Still Life with Lobster and Oysters.jpg|thumb|Artistic vision: ''[[Still Life]] with [[Lobster]] and [[Oyster]]s'' by [[Alexander Coosemans]], {{Circa|1660}}]] [446] => [447] => Animals have been the [[Animal style|subjects of art]] from the earliest times, both historical, as in [[Ancient Egypt]], and prehistoric, as in the [[Lascaux|cave paintings at Lascaux]]. Major animal paintings include [[Albrecht Dürer]]'s 1515 ''[[Dürer's Rhinoceros|The Rhinoceros]]'', and [[George Stubbs]]'s {{Circa|1762}} horse portrait ''[[Whistlejacket]]''.{{cite news |last1=Jones |first1=Jonathan |title=The top 10 animal portraits in art |url=https://www.theguardian.com/artanddesign/jonathanjonesblog/2014/jun/27/top-10-animal-portraits-in-art |access-date=24 June 2016 |newspaper=[[The Guardian]] |date=27 June 2014 |archive-url=https://web.archive.org/web/20160518105922/https://www.theguardian.com/artanddesign/jonathanjonesblog/2014/jun/27/top-10-animal-portraits-in-art |archive-date=18 May 2016 |url-status=live }} [[Arthropods in film|Insects]], birds and mammals play roles in literature and film,{{Cite journal |last1=Paterson |first1=Jennifer |title=Animals in Film and Media |url=https://www.oxfordbibliographies.com/view/document/obo-9780199791286/obo-9780199791286-0044.xml |journal=Oxford Bibliographies |access-date=24 June 2016 |date=29 October 2013 |doi=10.1093/obo/9780199791286-0044 |archive-url=https://web.archive.org/web/20160614200642/https://www.oxfordbibliographies.com/view/document/obo-9780199791286/obo-9780199791286-0044.xml |archive-date=14 June 2016 |url-status=live }} such as in [[Big bug movie|giant bug movies]].{{cite book |last1=Gregersdotter |first1=Katarina |last2=Höglund |first2=Johan |last3=Hållén |first3=Nicklas |title=Animal Horror Cinema: Genre, History and Criticism |url={{GBurl|id=hV-hCwAAQBAJ|p=147}} |date=2016 |publisher=Springer |isbn=978-1-137-49639-3 |page=147}}{{cite book |last1=Warren |first1=Bill |last2=Thomas |first2=Bill |title=Keep Watching the Skies!: American Science Fiction Movies of the Fifties, The 21st Century Edition |url={{GBurl|id=B7kUCwAAQBAJ|pg=PT32}} |date=2009 |publisher=[[McFarland & Company]] |isbn=978-1-4766-2505-8 |page=32}}{{cite book |last=Crouse |first=Richard |title=Son of the 100 Best Movies You've Never Seen |url={{GBurl|id=B5alnowvF3sC|pg=PT200}} |year=2008 |publisher=ECW Press |isbn=978-1-55490-330-6 |page=200}} [448] => [449] => Animals including [[Insects in mythology|insects]] and mammals are featured in mythology and religion. In both Japan and Europe, a [[butterfly]] was seen as the personification of a person's soul,{{cite book |last=Hearn |first=Lafcadio |author-link=Lafcadio Hearn |year=1904 |title=Kwaidan: Stories and Studies of Strange Things |title-link=Kwaidan: Stories and Studies of Strange Things |publisher=Dover |isbn=978-0-486-21901-1}}{{Cite journal |url=https://quod.lib.umich.edu/cgi/t/text/text-idx?c=did;cc=did;rgn=main;view=text;idno=did2222.0001.694 |title=Butterfly |journal=Encyclopedia of Diderot and d'Alembert |access-date=10 July 2016 |date=January 2011 |last=Louis |first=Chevalier de Jaucourt (Biography) |archive-url=https://web.archive.org/web/20160811042437/https://quod.lib.umich.edu/cgi/t/text/text-idx?c=did;cc=did;rgn=main;view=text;idno=did2222.0001.694 |archive-date=11 August 2016 |url-status=live }}Hutchins, M., Arthur V. Evans, Rosser W. Garrison and Neil Schlager (Eds) (2003) Grzimek's Animal Life Encyclopedia, 2nd edition. Volume 3, Insects. Gale, 2003. while the [[Scarab (artifact)|scarab beetle]] was sacred in ancient Egypt.{{cite book |last=Ben-Tor |first=Daphna |title=Scarabs, A Reflection of Ancient Egypt |location=Jerusalem |publisher=Israel Museum |date=1989 |isbn=978-965-278-083-6 |page=8}} Among the mammals, [[Cattle in religion and mythology|cattle]],{{Cite news |last=Biswas |first=Soutik |title=Why the humble cow is India's most polarising animal |url=https://www.bbc.co.uk/news/world-asia-india-34513185 |publisher=BBC |access-date=9 July 2016 |date=2015-10-15 |archive-url=https://web.archive.org/web/20161122205058/https://www.bbc.co.uk/news/world-asia-india-34513185 |archive-date=22 November 2016 |url-status=live }} [[Deer in mythology|deer]],{{cite web |title=Deer |url=https://treesforlife.org.uk/forest/mythology-folklore/deer/ |publisher=[[Trees for Life (Scotland)|Trees for Life]] |access-date=23 June 2016 |archive-url=https://web.archive.org/web/20160614200842/https://treesforlife.org.uk/forest/mythology-folklore/deer/ |archive-date=14 June 2016 |url-status=live}} [[Horse worship|horses]],{{cite book |title=Hayagrīva: The Mantrayānic Aspect of Horse-cult in China and Japan |publisher=Brill Archive |page=9 |last=van Gulik |first=Robert Hans}} [[Cultural depictions of lions|lions]],{{cite web |last1=Grainger |first1=Richard |title=Lion Depiction across Ancient and Modern Religions |url=https://lionalert.org/page/Lion_Depiction_Across_Ancient_and_Modern_Religions |publisher=Alert |access-date=6 July 2016 |date=24 June 2012 |url-status=dead |archive-url=https://web.archive.org/web/20160923134807/https://lionalert.org/page/Lion_Depiction_Across_Ancient_and_Modern_Religions |archive-date=23 September 2016 }} [[Bat#Cultural significance|bats]],{{cite book |last1=Read |first1=Kay Almere |last2=Gonzalez |first2=Jason J. |year=2000 |title=Mesoamerican Mythology |publisher=[[Oxford University Press]] |pages=132–134}} [[bear worship|bears]],{{Cite journal |last=Wunn |first=Ina |s2cid=53595088 |date=January 2000 |title=Beginning of Religion |journal=Numen |volume=47 |issue=4 |pages=417–452 |doi=10.1163/156852700511612 }} and [[Wolves in folklore, religion and mythology|wolves]]{{cite book |last=McCone |first=Kim R. |chapter=Hund, Wolf, und Krieger bei den Indogermanen |editor=Meid, W. |title=Studien zum indogermanischen Wortschatz |location=Innsbruck |date=1987 |pages=101–154}} are the subjects of myths and worship. The [[signs of the zodiac|signs of the Western]] and [[Chinese zodiac]]s are also based on animals.{{cite book |last=Lau |first=Theodora |title=The Handbook of Chinese Horoscopes |pages=2–8, 30–35, 60–64, 88–94, 118–124, 148–153, 178–184, 208–213, 238–244, 270–278, 306–312, 338–344 |publisher=Souvenir Press |year=2005}}{{cite book |last=Tester |first=S. Jim |title=A History of Western Astrology |url={{GBurl|id=L0HSvH96alIC|p=31}} |year=1987 |publisher=Boydell & Brewer |isbn=978-0-85115-446-6 |pages=31–33 and passim}} [450] => [451] => == See also == [452] => [453] => * [[Animal coloration]] [454] => * [[Ethology]] [455] => * [[Lists of organisms by population]] [456] => * [[World Animal Day]], observed on October 4 [457] => [458] => == Notes == [459] => [460] => {{Notelist}} [461] => [462] => == References == [463] => [464] => {{Reflist}} [465] => [466] => == External links == [467] => [468] => {{Commons category|Animals}} [469] => [470] => {{Wikispecies|Animalia}} [471] => * [https://tolweb.org/ Tree of Life Project]. {{Webarchive|url=https://web.archive.org/web/20110612121424/http://www.tolweb.org//|date=12 June 2011}} [472] => * [https://animaldiversity.org/ Animal Diversity Web] – [[University of Michigan]]'s database of animals [473] => * [https://archive.today/20160426231847/https://www.arkive.org/ Wildscreen Arkive] – multimedia database of endangered/protected species [474] => [475] => {{Animalia}} [476] => {{Eukaryota}} [477] => {{Nature}} [478] => {{Life on Earth}} [479] => {{Organisms et al.}} [480] => [481] => {{Taxonbar |from=Q729}} [482] => {{Authority control}} [483] => [484] => [[Category:Animals| ]] [485] => [[Category:Kingdoms (biology)|Animals]] [486] => [[Category:Cryogenian first appearances]] [487] => [[Category:Taxa named by Carl Linnaeus]] [488] => [[Category:Biology terminology]] [] => )

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Animal

The Wikipedia page on "Animal" provides a comprehensive overview of the kingdom Animalia, which includes all multicellular organisms that are not part of the plant, fungus, or bacteria kingdoms. The page explores the diverse characteristics, classification, and evolution of animals, as well as their interactions with the environment and other organisms.

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The page explores the diverse characteristics, classification, and evolution of animals, as well as their interactions with the environment and other organisms. Starting with a definition of what constitutes an animal, the page delves into the key features shared by animals, such as being eukaryotic, heterotrophic, and having specialized tissues. It explains the hierarchical classification of animals, ranging from the major groups (phyla) down to individual species. The history of animal life on Earth is explored, from the early Ediacaran biota to the rapid diversification during the Cambrian explosion. The page discusses the evolutionary relationships among animals and highlights the major transitions that occurred, such as the development of tissues and the evolution of complex body plans. Additionally, the page examines the anatomy, physiology, and behavior of animals, looking at their unique adaptations to various habitats, locomotion, reproduction, and communication. It further explores the animal diet, covering the different feeding strategies employed by various species. The ecological role of animals and their interactions within ecosystems are discussed, including predator-prey relationships, symbiotic associations, and the impact of animals on nutrient cycling and ecosystem dynamics. The page also touches on the conservation of animal species and the threats they face from habitat destruction, pollution, and overexploitation. Furthermore, the Wikipedia page provides information on the human uses of animals, such as agriculture, biomedical research, companionship, and even cultural and religious practices involving animals. In conclusion, the Wikipedia page on "Animal" serves as a comprehensive resource for understanding the diverse and fascinating world of animals, covering their characteristics, classification, evolution, ecology, and their interactions with humans.

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