Editing Camel (section)

==Biology==
The average [[life expectancy]] of a camel is 40 to 50 years.<ref name="nationalgeo-bactrian">{{cite web | title = Bactrian Camel: Camelus bactrianus | work = National Geographic | date = 10 May 2011 | access-date = 28 November 2012 | url = http://animals.nationalgeographic.com/animals/mammals/bactrian-camel/ | url-status = dead | archive-url = https://web.archive.org/web/20121104103313/http://animals.nationalgeographic.com/animals/mammals/bactrian-camel | archive-date = 4 November 2012 }}</ref> A full-grown adult dromedary camel stands {{convert|1.85|m|ftin|abbr=on}} at the shoulder and {{convert|2.15|m|ftin|abbr=on}} at the hump.<ref name=camello>{{cite web| publisher = Camello Safari | title = The amazing characteristics of the camels | access-date = 26 November 2012 | url = http://www.camellosafari.com/?page_id=251 | url-status = live | archive-url = https://web.archive.org/web/20121107134110/http://www.camellosafari.com/?page_id=251 | archive-date = 7 November 2012}}</ref> Bactrian camels can be a foot taller. Camels can run at up to {{convert|65|km/h|mi/h|0|abbr=on}} in short bursts and sustain speeds of up to {{convert|40|km/h|mi/h|0|abbr=on}}.<ref name=bigfacts>{{cite web| title = How Fast Can Camels Run and How Long Can They Run For? | work = Big Site of Amazing Facts | date = 17 April 2010 | access-date = 29 November 2012 | url = http://www.bigsiteofamazingfacts.com/how-fast-can-camels-run-and-how-long-can-they-run-for/}}</ref> Bactrian camels weigh {{convert|300|to|1000|kg|lbs|abbr=on}} and dromedaries {{convert|300|to|600|kg|lbs|abbr=on}}. The widening toes on a camel's [[hoof]] provide supplemental grip for varying soil sediments.<ref>{{cite web |last1=Fayed |first1=R. H. |title=Adaptation of the Camel to Desert environment |url=https://esarf2.tripod.com/conf2001proc.htm |website=ESARF |access-date=21 April 2025}}</ref>

The male dromedary camel has an organ called a ''dulla'' in his throat, a large, inflatable sac that he extrudes from his mouth when in [[rut (mammalian reproduction)|rut]] to assert dominance and attract females. It resembles a long, swollen, pink tongue hanging out of the side of the camel's mouth.<ref>{{cite journal |journal= Injury |volume= 43 |issue= 9 |pages= 1617–1620 |title= Camel bite injuries in United Arab Emirates: A 6 year prospective study |first1= Fikri M. |last1= Abu-Zidana |first2= Hani O. |last2= Eida |first3= Ashraf F. |last3= Hefnya |first4= Masoud O. |last4= Bashira |first5= Frank |last5= Branickia |doi= 10.1016/j.injury.2011.10.039 |pmid= 22186231 |date= 18 December 2011 |quote= The male mature camel has a specialized inflatable diverticulum of the soft palate called the "Dulla". and During rutting the Dulla enlarges on filling with air from the trachea until it hangs out of the mouth of the camel and comes to resemble a pink ball. This occurs in only the one-humped camel. Copious saliva turns to foam covering the mouth as the male gurgles and makes metallic sounds. [6 cites to 5 references omitted]}}</ref> Camels mate by having both male and female sitting on the ground, with the male mounting from behind.<ref>{{cite video|url=https://www.youtube.com/watch?v=mqxQbUMV8zQ|title=Two Male Camels Fighting Over One Female|website=Youtube.com|access-date=2016-01-08|url-status=live|archive-url=https://web.archive.org/web/20151219060529/https://www.youtube.com/watch?v=mqxQbUMV8zQ|archive-date=2015-12-19}}</ref> The male usually [[ejaculates]] three or four times within a single mating session.<ref name=mukasa81 /> Camelids are the only ungulates to mate in a sitting position.<ref name=sandiegozoo>{{cite web | publisher = San Diego Zoo Global Library | title = Bactrian & Dromedary Camels | work = Factsheets | access-date = 4 December 2012 | date = March 2009 | url = http://library.sandiegozoo.org/factsheets/camel/camel.htm | archive-url = https://web.archive.org/web/20120922092103/http://library.sandiegozoo.org/factsheets/camel/camel.htm | archive-date = 22 September 2012 }}</ref>{{anchor|Eco-behavioral adaptations}}

===Ecological and behavioral adaptations===
{{anchor |Hump}}

[[File:Teve 3.jpg |thumb |Camel humps store fat for when food is scarce. If a camel uses the fat, the hump becomes limp and droops.]]

It is a common myth that a camel stores water in its hump,<ref>{{cite web|url=https://www.loc.gov/everyday-mysteries/zoology/item/how-much-water-does-a-camels-hump-hold/#:~:text=A%20camel's%20hump%20does%20not,become%20limp%20and%20droop%20down.|publisher=Library of Congress|accessdate=2025-05-06|title=How much water does a camel’s hump hold?}}</ref> but the humps in fact are reservoirs of fatty tissue, which can be used as a reserve source of calories, not water.  When this tissue is metabolized, it yields a greater mass of water than that of the fat processed. This [[lipolysis |fat metabolization]], while releasing energy, causes water to evaporate from the lungs during [[breathing |respiration]] (as oxygen is required for the metabolic process): overall, there is a net decrease in water.<ref name=vannjones>{{cite web |url=http://www.djur.cob.lu.se/Djurartiklar/Kamel.html |title=What secrets lie within the camel's hump? |first=Kerstin |last=Vann Jones |publisher=[[Lund University]] |location=[[Sweden]] |access-date=7 January 2008 |url-status=live |archive-url=https://web.archive.org/web/20090523104134/http://www.djur.cob.lu.se/Djurartiklar/Kamel.html |archive-date=23 May 2009}}</ref><ref name=rastogi71>{{cite book |publisher=[[New Age International]] |isbn=9788122412796 |last=Rastogi |first=S. C. |title=Essentials Of Animal Physiology |year=1971 |pages=180–181}}</ref>

[[File:Camel portrait.jpg |upright |thumb |alt=A portrait of a camel with a visibly thick mane |A camel's thick coat is one of its many adaptations that aid it in desert-like conditions.<!---Don't move this image up or it causes a break in the text on wide screens--->]]
[[File:Eylcamel.jpg |thumb |alt=A leashed pack camel |A camel in [[wildlife of Somalia |Somalia]], which has the world's largest camel population<ref name="Bernstein"/>]]
Camels have a series of physiological adaptations that allow them to withstand long periods of time without any external source of water.<ref name="roberts86">{{cite book |last=Roberts |first=Michael Bliss Vaughan |title=Biology: A Functional Approach |publisher=[[Nelson Thornes]] |year=1986 |isbn=9780174480198 |pages=234–235, 241}}</ref> The dromedary camel can drink as seldom as once every 10 days even under very hot conditions, and can lose up to 30% of its body mass due to dehydration.<ref>{{Cite web |url=http://unesdoc.unesco.org/images/0022/002240/224033e.pdf |archive-url=https://web.archive.org/web/20151109175143/http://unesdoc.unesco.org/images/0022/002240/224033e.pdf |archive-date=2015-11-09 |url-status=live |title=The Camel from Tradition To Modern Times |author=[[UNESCO]] }}</ref> They can drink up to 20 gallons at a time but this is stored in the animal's bloodstream, not, as popularly believed, in its humps.<ref>{{cite web|url=https://www.loc.gov/everyday-mysteries/zoology/item/how-much-water-does-a-camels-hump-hold/#:~:text=A%20camel's%20hump%20does%20not,become%20limp%20and%20droop%20down.|publisher=Library of Congress|accessdate=2025-05-06|title=How much water does a camel’s hump hold?}}</ref>

Unlike other mammals, camels' [[red blood cell]]s are oval rather than circular in shape. This facilitates the flow of red blood cells during dehydration<ref>{{cite journal |last1=Eitan |first1=A |last2=Aloni |first2=B |last3=Livne |first3=A |title=Unique properties of the camel erythrocyte membraneII. Organization of membrane proteins |journal=[[Biochimica et Biophysica Acta (BBA) - Biomembranes]] |volume=426 |issue=4 |pages=647–58 |year=1976 |doi=10.1016/0005-2736(76)90129-2 |pmid=816376 }}</ref> and makes them better at withstanding high [[osmosis |osmotic]] variation without rupturing when drinking large amounts of water.<ref>{{cite web |url=http://www.zoo-hannover.de/zoo-hannover/en/zoo_v3/tiere_attraktionen/tiere_az/tiere_detail_726.html |archive-url=https://web.archive.org/web/20051025001139/http://www.zoo-hannover.de/zoo-hannover/en/zoo_v3/tiere_attraktionen/tiere_az/tiere_detail_726.html |archive-date=25 October 2005 |title= Dromedary |publisher=Hannover Zoo |access-date=8 January 2008}}</ref><ref name=mares99>{{cite book |publisher=University of Oklahoma Press |isbn=9780806131467 |editor1-last=Mares |editor2-last=Michael A. |title=Deserts |year=1999 |chapter=Camel |pages=96–97 |first=E. Anette |last=Halpern |chapter-url=https://books.google.com/books?id=g3CbqZtaF4oC&pg=PA96 |url-status=live |archive-url=https://web.archive.org/web/20160429083434/https://books.google.com/books?id=g3CbqZtaF4oC&lpg=PP1&pg=PA96 |archive-date=2016-04-29}}</ref>

Camels are able to withstand changes in [[body temperature]] and water consumption that would kill most other mammals. Their temperature ranges from {{convert |34 |°C |°F |0 |abbr=on}} at dawn and steadily increases to {{convert |40 |°C |°F |0 |abbr=on}} by sunset, before they cool off at night again.<ref name=roberts86 /> In general, to compare between camels and the other livestock, camels lose only 1.3 liters of fluid intake every day while the other livestock lose 20 to 40 liters per day.<ref>Breulmann, M., Böer, B., Wernery, U., Wernery, R., El Shaer, H., Alhadrami, G., ... Norton, J. (2007). "The Camel From Tradition to Modern Times" (PDF). [[UNESCO]] DOHA OFFICE.</ref> Maintaining the brain temperature within certain limits is critical for animals; to assist this, camels have a [[rete mirabile]], a complex of arteries and veins lying very close to each other which utilizes countercurrent blood flow to cool blood flowing to the brain.<ref name="Inside Nature's Giants">[[Inside Nature's Giants]]. [[Channel 4 (UK)]] documentary. Transmitted 30 August 2011</ref> Camels rarely sweat, even when ambient temperatures reach {{convert |49 |°C |°F |0 |abbr=on}}.<ref name="nationalgeo-dromedary">{{cite web |title=Arabian (Dromedary) Camel |access-date=25 November 2012 |publisher=[[National Geographic Society]] |work=National Geographic |date=10 May 2011 |url=http://animals.nationalgeographic.com/animals/mammals/dromedary-camel/ |url-status=dead |archive-url=https://web.archive.org/web/20121119062839/http://animals.nationalgeographic.com/animals/mammals/dromedary-camel |archive-date=19 November 2012}}</ref> Any sweat that does occur evaporates at the skin level rather than at the surface of their coat; the [[heat of vaporization]] therefore comes from body heat rather than ambient heat. Camels can withstand losing 25% of their body weight in water, whereas most other mammals can withstand only about 12–14% dehydration before [[Congestive heart failure |cardiac failure]] results from circulatory disturbance.<ref name=mares99/>

When the camel exhales, [[water vapor]] becomes trapped in their [[nostrils]] and is reabsorbed into the body as a means to conserve water.<ref>{{cite news |url=https://www.nytimes.com/1981/07/12/travel/a-pilgrimage-to-a-mystic-s-hermitage-in-algeria.html |title=A Pilgrimage To A Mystic's Hermitage In Algeria |newspaper= [[The New York Times]] |date=12 July 1981 |access-date=7 March 2009 |first=Paul |last=Lewis |url-status=live |archive-url=https://web.archive.org/web/20090804093505/http://www.nytimes.com/1981/07/12/travel/a-pilgrimage-to-a-mystic-s-hermitage-in-algeria.html |archive-date=4 August 2009 }}</ref> Camels eating green herbage can ingest sufficient moisture in milder conditions to maintain their bodies' hydrated state without the need for drinking.<ref name=fao94>{{cite book |chapter-url=http://www.fao.org/docrep/t0690e/t0690e09.htm |title=A manual for primary animal health care worker |chapter=Camels, llamas and alpacas |year=1994 |series=[[FAO Animal Health Manual]] |publisher=[[FAO Agriculture and Consumer Protection]] |url-status=live |archive-url=https://web.archive.org/web/20080727212250/http://www.fao.org/docrep/t0690e/t0690e09.htm |archive-date=2008-07-27}}</ref>

[[File:Camels in Dubai 2.jpg |right |thumb |Domesticated camel calves lying in sternal recumbency, which aids heat loss]]
The camel's thick coat insulates it from the intense heat radiated from desert sand; a shorn camel must sweat 50% more to avoid overheating.<ref>{{cite book |last=Schmidt-Nielsen |first=K. |year=1964 |title=Desert Animals: Physiological Problems of Heat and Water |location=New York |publisher=[[Oxford University Press]] (OUP)}} Cited in {{cite web |url=http://www.bio.davidson.edu/Courses/anphys/1999/Blackwell/Fur.htm |title=Coat of fur on the camel |archive-url=https://web.archive.org/web/20030225103329/http://www.bio.davidson.edu/Courses/anphys/1999/Blackwell/Fur.htm |archive-date=February 25, 2003 |website=[[Davidson College]]}}</ref> During the summer the coat becomes lighter in color, reflecting light as well as helping avoid sunburn.<ref name=mares99 /> The camel's long legs help by keeping its body farther from the ground, which can heat up to {{convert |70 |°C |°F |0 |abbr=on}}.<ref name=bronxzoo>{{cite web |author=Bronx Zoo |title=Camel Adaptations |access-date=29 November 2012 |url=http://www.bronxzoo.com/files/engage.html |publisher=[[Wildlife Conservation Society]] |format=Flash |archive-url=https://web.archive.org/web/20120626071454/http://www.bronxzoo.com/files/engage.html |archive-date=26 June 2012}}</ref><ref name=rundel05>{{cite book |publisher=[[Cambridge University Press]] (CUP) |isbn=9780521021418 |last1=Rundel |first1=Philip Wilson |first2=Arthur C. |last2=Gibson |title=Ecological Communities And Processes in a Mojave Desert Ecosystem: Rock Valley, Nevada |date=30 September 2005 |chapter=Adaptations of Mojave Desert Animals |page=130 }}</ref> Dromedaries have a pad of thick tissue over the [[sternum]] called the ''pedestal''. When the animal lies down in a sternal recumbent position, the pedestal raises the body from the hot surface and allows cooling air to pass under the body.<ref name="Inside Nature's Giants"/>

Camels' mouths have a thick leathery lining, allowing them to chew thorny desert plants. Long eyelashes and ear hairs, together with nostrils that can close, form a barrier against sand. If sand gets lodged in their eyes, they can dislodge it using their translucent [[third eyelid]] (also known as the nictitating membrane). The camels' gait and widened feet help them move without sinking into the sand.<ref name=bronxzoo /><ref name=silverstein08>{{cite book |publisher=Twenty-First Century Books |isbn=9780822534341 |last1=Silverstein |first1=Alvin |first2=Virginia B |last2=Silverstein |first3=Virginia |last3=Silverstein<!--No, really.--> |first4=Laura |last4=Silverstein Nunn |title=Adaptation |year=2008 |pages=[https://archive.org/details/adaptation0000silv/page/42 42–43] |url=https://archive.org/details/adaptation0000silv/page/42 }}</ref>

The [[kidney]]s and [[intestines]] of a camel are very efficient at reabsorbing water. Camels' kidneys have a 1:4 [[Renal cortex |cortex]] to [[Renal medulla |medulla ratio]].<ref>{{Cite web |url=https://www.researchgate.net/publication/249746665 |title=Morphometric analysis of heart, kidneys and adrenal glands in dromedary camel calves (PDF Download Available) |website=ResearchGate |language=en |access-date=2017-03-03 |url-status=live |archive-url=https://web.archive.org/web/20170304040835/https://www.researchgate.net/publication/249746665_Morphometric_analysis_of_heart_kidneys_and_adrenal_glands_in_dromedary_camel_calves |archive-date=2017-03-04}}</ref> Thus, the medullary part of a camel's kidney occupies twice as much area as a cow's kidney. Secondly, [[renal corpuscles]] have a smaller diameter, which reduces surface area for filtration. These two major anatomical characteristics enable camels to conserve water and limit the volume of urine in extreme desert conditions.<ref name="Rehan08">Rehan S and AS Qureshi, 2006. Microscopic evaluation of the heart, kidneys and adrenal glands of one-humped camel calves (Camelus dromedarius) using semi automated image analysis system. J Camel Pract Res. 13(2): 123
</ref> [[Camel urine]] comes out as a thick syrup, and camel faeces are so dry that they do not require drying when used to fuel fires.<ref name=davidson06 /><ref name="davidson-kidney">{{cite web |url=http://www.bio.davidson.edu/Courses/anphys/1999/Blackwell/Kidney.htm |publisher=Davidson College |title=Kidneys and Concentrated Urine |work= Temperature and Water Relations in Dromedary Camels (Camelus dromedarius) |archive-url=https://web.archive.org/web/20030225104431/http://www.bio.davidson.edu/Courses/anphys/1999/Blackwell/Kidney.htm |archive-date=February 25, 2003}}</ref><ref name=junglestore>{{cite web |title=Fun facts about the Camel |work=The Jungle Store |access-date=3 December 2012 |url=http://www.thejunglestore.com/Camels |archive-url=https://web.archive.org/web/20121117070148/http://www.thejunglestore.com/Camels |archive-date=17 November 2012 }}</ref><ref name=fedewa00 />

The camel [[immune system]] differs from those of other mammals. Normally, the Y-shaped [[antibody]] molecules consist of two heavy (or long) chains along the length of the Y, and two light (or short) chains at each tip of the Y.<ref name="Camelized" /> Camels, in addition to these, also have antibodies made of only two heavy chains, a trait that makes them smaller and more durable.<ref name="Camelized" /> These "heavy-chain-only" antibodies, discovered in 1993, are thought to have developed 50&nbsp;million years ago, after camelids split from ruminants and pigs.<ref name="Camelized" >{{cite journal |last1=Koenig |first1=R. |department=Veterinary Medicine |title='Camelized' Antibodies Make Waves |journal=[[Science (journal) |Science]] |volume=318 |issue=5855 |page=1373 |year=2007 |pmid=18048665 |doi=10.1126/science.318.5855.1373 |s2cid=71028674}}</ref>

The parasite ''[[Trypanosoma evansi]]'' causes the disease [[surra]] in camels.<ref name="Sazmand-Joachim-2017">{{cite journal |last1=Sazmand |first1=Alireza |last2=Joachim |first2=Anja |title=Parasitic diseases of camels in Iran (1931–2017) – a literature review |journal=[[Parasite (journal) |Parasite]] |publisher=[[EDP Sciences]] |volume=24 |year=2017 |issn=1776-1042 |doi=10.1051/parasite/2017024 |pages=1–15 |s2cid=13783061 |pmid=28617666 |pmc=5479402 |id=Article Number 21}}</ref>{{RP |page=2}}

===Genetics===
The [[karyotype]]s of different camelid species have been studied earlier by many groups,<ref>{{cite journal |last1=Taylor |first1=K.M. |last2=Hungerford |first2=D.A. |last3=Snyder |first3=R.L. |last4=Ulmer Jr. |first4=F.A. |title=Uniformity of karyotypes in the Camelidae |journal=Cytogenetic and Genome Research |volume=7 |issue=1 |pages=8–15 |year=1968 |doi=10.1159/000129967 |pmid=5659175}}</ref><ref>{{cite journal |last1=Koulischer |first1=L |last2=Tijskens |first2=J |last3=Mortelmans |first3=J |title=Mammalian cytogenetics. IV. The chromosomes of two male Camelidae: Camelus bactrianus and Lama vicugna. |journal=Acta Zoologica et Pathologica Antverpiensia |volume=52 |pages=89–92 |year=1971 |pmid=5163286}}</ref><ref>{{cite journal |last1=Bianchi |first1=N. O. |last2=Larramendy |first2=M. L. |last3=Bianchi |first3=M. S. |last4=Cortés |first4=L. |title=Karyological conservatism in South American camelids |journal=Experientia |volume=42 |issue=6 |pages=622–4 |year=1986 |doi=10.1007/BF01955563|s2cid=23440910 }}</ref><ref>{{cite journal |first1=Thomas D. |last1=Bunch |first2=Warren C. |last2=Foote |first3=Alma |last3=Maciulis |year=1985 |title=Chromosome banding pattern homologies and NORs for the Bactrian camel, guanaco, and llama |journal=Journal of Heredity |volume=76 |issue=2 |pages=115–8 |doi=10.1093/oxfordjournals.jhered.a110034 }}</ref><ref>{{cite book |editor1-first=Stephen J. |editor1-last=O'Brien |editor2-first=Joan C. |editor2-last=Menninger |editor3-first=William G. |editor3-last=Nash |year=2006 |title=Atlas of Mammalian Chromosomes |url=https://archive.org/details/atlasmammalianch00obri |url-access=limited |location=New York |publisher=Wiley-Liss |isbn=978-0-471-35015-6 |page=[https://archive.org/details/atlasmammalianch00obri/page/n589 547]}}</ref><ref>{{cite journal |last1=Di Berardino |first1=D. |last2=Nicodemo |first2=D. |last3=Coppola |first3=G. |last4=King |first4=A.W. |last5=Ramunno |first5=L. |last6=Cosenza |first6=G.F. |last7=Iannuzzi |first7=L. |last8=Di Meo |first8=G.P. |last9=Balmus |first9=G. | display-authors = 8|title=Cytogenetic characterization of alpaca (''Lama pacos'', fam. Camelidae) prometaphase chromosomes |journal=Cytogenetic and Genome Research |volume=115 |issue=2 |pages=138–44 |year=2006 |pmid=17065795 |doi=10.1159/000095234|s2cid=21378633 }}</ref> but no agreement on chromosome nomenclature of camelids has been reached. A 2007 study [[flow sorting|flow sorted]] camel chromosomes, building on the fact that camels have 37 pairs of chromosomes (2n=74), and found that the karyotype consisted of one [[Centromere#Metacentric|metacentric]], three submetacentric, and 32 acrocentric autosomes. The [[Y chromosome|Y]] is a small metacentric chromosome, while the [[X chromosome|X]] is a large metacentric chromosome.<ref>{{cite journal |last1=Balmus |first1=Gabriel |last2=Trifonov |first2=Vladimir A. |last3=Biltueva |first3=Larisa S. |last4=O'Brien |first4=Patricia C.M. |last5=Alkalaeva |first5=Elena S. |last6=Fu |first6=Beiyuan |last7=Skidmore |first7=Julian A. |last8=Allen |first8=Twink |last9=Graphodatsky |first9=Alexander S. | display-authors = 8|title=Cross-species chromosome painting among camel, cattle, pig and human: further insights into the putative Cetartiodactyla ancestral karyotype |journal=Chromosome Research |volume=15 |issue=4 |pages=499–515 |year=2007 |pmid=17671843 |doi=10.1007/s10577-007-1154-x|s2cid=23226488 }}</ref>
[[File:Camel skull.jpg|thumb|right|Skull of an F1 hybrid camel, [[Museum of Osteology]], Oklahoma]]
The [[hybrid camel]], a hybrid between Bactrian and dromedary camels, has one hump, though it has an indentation {{convert|4|–|12|cm|in|abbr=on}} deep that divides the front from the back. The hybrid is {{convert|2.15|m|ftin|abbr=on}} at the shoulder and {{convert|2.32|m|ftin|abbr=on}} tall at the hump. It weighs an average of {{convert|650|kg|lb|abbr=on}} and can carry around {{convert|400|to|450|kg|lb|abbr=on}}, which is more than either the dromedary or Bactrian can.<ref name=potts>{{cite journal|url=http://www.silkroadfoundation.org/newsletter/vol3num1/7_bactrian.php|title=Bactrian Camels and Bactrian-Dromedary Hybrids|last=Potts|first=Danel|journal=Silkroad|volume=3|issue=1|archive-url=https://web.archive.org/web/20160623020952/http://www.silkroadfoundation.org/newsletter/vol3num1/7_bactrian.php|archive-date=2016-06-23|access-date=2012-11-29}}</ref>

According to molecular data, the wild Bactrian camel (''C. ferus'') separated from the domestic Bactrian camel (''C. bactrianus'') about 1 million years ago.<ref>{{Cite journal|last1=Mohandesan|first1=Elmira|last2=Fitak|first2=Robert R.|last3=Corander|first3=Jukka|last4=Yadamsuren|first4=Adiya|last5=Chuluunbat|first5=Battsetseg|last6=Abdelhadi|first6=Omer|last7=Raziq|first7=Abdul|last8=Nagy|first8=Peter|last9=Stalder|first9=Gabrielle|date=30 August 2017|title=Mitogenome Sequencing in the Genus Camelus Reveals Evidence for Purifying Selection and Long-term Divergence between Wild and Domestic Bactrian Camels|journal=[[Scientific Reports]]|language=En|volume=7|issue=1|pages=9970|doi=10.1038/s41598-017-08995-8|pmid=28855525|issn=2045-2322|pmc=5577142|bibcode=2017NatSR...7.9970M}}</ref><ref>{{Cite journal|last1=Ji|first1=R|last2=Cui|first2=P|last3=Ding|first3=F|last4=Geng|first4=J|last5=Gao|first5=H|last6=Zhang|first6=H|last7=Yu|first7=J|last8=Hu|first8=S|last9=Meng|first9=H|date=August 2009|title=Monophyletic origin of domestic bactrian camel (Camelus bactrianus) and its evolutionary relationship with the extant wild camel (Camelus bactrianus ferus)|journal=Animal Genetics|volume=40|issue=4|pages=377–382|doi=10.1111/j.1365-2052.2008.01848.x|issn=0268-9146|pmc=2721964|pmid=19292708}}</ref> New World and Old World camelids diverged about 11 million years ago.<ref>{{cite journal |last1=Stanley |first1=H. F. |last2=Kadwell |first2=M. |last3=Wheeler |first3=J. C. |title=Molecular Evolution of the Family Camelidae: A Mitochondrial DNA Study |journal=Proceedings of the Royal Society B: Biological Sciences |volume=256 |issue=1345 |pages=1–6 |year=1994 |doi=10.1098/rspb.1994.0041|pmid=8008753 |bibcode=1994RSPSB.256....1S |s2cid=40857282 }}</ref> In spite of this, these species can hybridize and produce viable offspring.<ref>{{cite journal |last1=Skidmore |first1=J. A. |last2=Billah |first2=M. |last3=Binns |first3=M. |last4=Short |first4=R. V. |last5=Allen |first5=W. R. |title=Hybridizing Old and New World camelids: Camelus dromedarius x Lama guanicoe |journal=Proceedings of the Royal Society B: Biological Sciences |volume=266 |issue=1420 |pages=649–56 |year=1999 |doi=10.1098/rspb.1999.0685 |pmid=10331286 |pmc=1689826}}</ref> The [[Cama (animal)|cama]] is a camel-llama hybrid bred by scientists to see how closely related the parent species are.<ref name="bbc-came">{{cite news | title = Meet Rama the cama ... | publisher = BBC | access-date = 29 November 2012 | date = 21 January 1998 | url = http://news.bbc.co.uk/2/hi/science/nature/49301.stm | url-status = live | archive-url = https://web.archive.org/web/20121023042733/http://news.bbc.co.uk/2/hi/science/nature/49301.stm | archive-date = 23 October 2012 }}</ref> Scientists [[collected semen]] from a camel via an artificial vagina and inseminated a llama after stimulating ovulation with [[gonadotrophin]] injections.<ref name=fahmy02>{{cite web|title='Cama' camel/llama hybrids born in UAE research centre |url=http://www.royalsociety.org.nz/2002/03/21/emirates-cama/ |first=Miral |last=Fahmy |date=21 March 2002 |access-date=28 November 2012 |work=Science in the News |publisher=The Royal Society of New Zealand |archive-url=https://web.archive.org/web/20130927105152/http://www.royalsociety.org.nz/2002/03/21/emirates-cama/ |archive-date=27 September 2013 }}</ref> The cama is halfway in size between a camel and a llama and lacks a hump. It has ears intermediate between those of camels and llamas, longer legs than the llama, and partially [[cloven-hoof|cloven hooves]].<ref name=campbell05>{{cite news | url=https://www.theguardian.com/world/2002/jul/15/highereducation.science | title=Bad karma for cross llama without a hump | newspaper=The Guardian | first=Duncan | last=Campbell | date=15 July 2002 | access-date=2 March 2009 | location=London | url-status=live | archive-url=https://web.archive.org/web/20130826054716/http://www.theguardian.com/world/2002/jul/15/highereducation.science | archive-date=26 August 2013 }}</ref><ref name=metrouk>{{cite web | title = Joy for world's first camel and llama cross | work = Metro UK | access-date = 29 November 2012 | url = http://www.metro.co.uk/news/136134-joy-for-world-s-first-camel-and-llama-cross | date = 6 April 2008 | url-status = live | archive-url = https://web.archive.org/web/20121125032426/http://www.metro.co.uk/news/136134-joy-for-world-s-first-camel-and-llama-cross | archive-date = 25 November 2012 }}</ref> Like the [[mule]], camas are sterile, despite both parents having the same number of chromosomes.<ref name="fahmy02"/>

===Evolution===
The earliest known camel, called ''[[Protylopus]]'', lived in North America 40 to 50 million years ago (during the [[Eocene]]).<ref name=mukasa81 /> It was about the size of a rabbit and lived in the open woodlands of what is now [[South Dakota]].<ref name=harington97>{{cite web|last=Harington |first=C. R. |title=Ice Age Yukon and Alaskan Camels |work=Yukon Beringia Interpretive Centre |access-date=3 December 2012 |date=June 1997 |url=http://www.beringia.com/research/camels.html |publisher=Government of Yukon, Department of Tourism and Culture, Museums Unit |archive-url=https://web.archive.org/web/20130126013451/http://www.beringia.com/research/camels.html |archive-date=26 January 2013 }}</ref><ref name=bernstein09>{{cite book | publisher = Grove Press | isbn = 9780802144164 | last = Bernstein | first = William J. | title = A Splendid Exchange: How Trade Shaped the World | date = 6 May 2009 |pages=54–55 }}</ref> By 35 million years ago, the ''[[Poebrotherium]]'' was the size of a goat and had many more traits similar to camels and llamas.<ref name=northdakota>{{cite web |website=North Dakota Industrial Commission Department of Mineral Resources |title=''Poebrotherium'' |url=https://www.dmr.nd.gov/ndfossil/poster/PDF/Poebrotherium.pdf |access-date=3 December 2012 |archive-url=https://web.archive.org/web/20120725092634/https://www.dmr.nd.gov/ndfossil/Poster/PDF/Poebrotherium.pdf |archive-date=25 July 2012}}</ref><ref name=scibuzz04>{{cite web | publisher = Science Museum of Minnesota | title = Fossil camel skull (Poebrotherium sp.) | work = Science Buzz | access-date = 3 December 2012 | date = January 2004 | url = http://www.sciencebuzz.org/museum/object/2004_01_fossil_camel_skull_poebrotherium | url-status = live | archive-url = https://web.archive.org/web/20121014130040/http://www.sciencebuzz.org/museum/object/2004_01_fossil_camel_skull_poebrotherium | archive-date = 14 October 2012 }}</ref> The hoofed ''[[Stenomylus]]'', which walked on the tips of its toes, also existed around this time, and the long-necked ''[[Aepycamelus]]'' evolved in the [[Miocene]].<ref name=kindersley08>{{cite encyclopedia | publisher = Penguin | isbn = 9780756682415 | last = Kindersley | first = Dorling | encyclopedia = Encyclopedia of Dinosaurs and Prehistoric Life |title=Camels |pages=266–7 | date = 2 June 2008 }}</ref> The split between the tribes [[Camelini]], which contains modern camels and [[Lamini]], modern [[llama]]s, [[alpaca]]s, [[vicuña]]s, and [[guanaco]]s, is estimated to have occurred over 16 million years ago.<ref>{{Cite journal |last1=Lynch |first1=Sinéad |last2=Sánchez-Villagra |first2=Marcelo R. |last3=Balcarcel |first3=Ana |date=December 2020 |title=Description of a fossil camelid from the Pleistocene of Argentina, and a cladistic analysis of the Camelinae |journal=[[Swiss Journal of Palaeontology]] |language=en |volume=139 |issue=1 |page=5 |doi=10.1186/s13358-020-00208-6 |issn=1664-2376 |pmc=7590954 |pmid=33133011 |bibcode=2020SwJP..139....8L |doi-access=free }}</ref>

The ancestor of modern camels, ''[[Paracamelus]]'', migrated into Eurasia from North America via [[Beringia]] during the late Miocene, between 7.5 and 6.5 million years ago.<ref>{{Cite journal|last1=Heintzman|first1=Peter D.|last2=Zazula|first2=Grant D.|last3=Cahill|first3=James A.|last4=Reyes|first4=Alberto V.|last5=MacPhee|first5=Ross D.E.|last6=Shapiro|first6=Beth|date=September 2015|title=Genomic Data from Extinct North American Camelops Revise Camel Evolutionary History|url=https://escholarship.org/content/qt4zm8b6kj/qt4zm8b6kj.pdf?t=nwxn49|journal=Molecular Biology and Evolution|language=en|volume=32|issue=9|pages=2433–2440|doi=10.1093/molbev/msv128|pmid=26037535|issn=0737-4038}}</ref><ref name="RybczynskiEtAl2013">{{Cite journal|last1=Rybczynski|first1=Natalia|last2=Gosse|first2=John C.|last3=Richard Harington|first3=C.|last4=Wogelius|first4=Roy A.|last5=Hidy|first5=Alan J.|last6=Buckley|first6=Mike|date=June 2013|title=Mid-Pliocene warm-period deposits in the High Arctic yield insight into camel evolution|journal=Nature Communications|language=en|volume=4|issue=1|pages=1550|doi=10.1038/ncomms2516|issn=2041-1723|pmc=3615376|pmid=23462993|bibcode=2013NatCo...4.1550R}}</ref><ref name="singh-tomar">{{cite book | edition = 8th revised | publisher = Rastogi Publications | isbn = 9788171336395 | author1 = Singh | author2 = Tomar | title = Evolutionary Biology | location = New Delhi |page=334}}</ref> During the Pleistocene, around 3 to 1 million years ago, the North American Camelidae spread to South America as part of the [[Great American Interchange]] via the newly formed [[Isthmus of Panama]], where they gave rise to [[guanacos]] and related animals.<ref name=mukasa81 /><ref name=harington97/><ref name=bernstein09/> Populations of ''Paracamelus'' continued to exist in the North American Arctic into the [[Early Pleistocene]].<ref name="RybczynskiEtAl2013"/><ref>{{Cite journal|last1=Buckley|first1=Michael|last2=Lawless|first2=Craig|last3=Rybczynski|first3=Natalia|date=March 2019|title=Collagen sequence analysis of fossil camels, Camelops and c.f. Paracamelus, from the Arctic and sub-Arctic of Plio-Pleistocene North America|url=https://pure.manchester.ac.uk/ws/files/85598334/BuckleyCamelopsPaper_AAM.pdf|journal=Journal of Proteomics|language=en|volume=194|pages=218–225|doi=10.1016/j.jprot.2018.11.014|pmid=30468917|s2cid=53713960}}</ref> This creature is estimated to have stood around {{convert|9|ft|m|abbr=off|spell=in}} tall. The Bactrian camel diverged from the dromedary about 1 million years ago, according to the fossil record.<ref>{{Cite journal|last1=Geraads|first1=Denis|last2=Didier|first2=Gilles|last3=Barr|first3=Andrew|last4=Reed|first4=Denne|last5=Laurin|first5=Michel|date=April 2020|title=The fossil record of camelids demonstrates a late divergence between Bactrian camel and dromedary=Acta Palaeontologica Polonica|journal=Acta Palaeontologica Polonica|language=en|volume=65|issue=2|pages=251–260|doi=10.4202/app.00727.2020|issn=0567-7920|eissn=1732-2421|doi-access=free}}</ref>

The last camel native to North America was ''[[Camelops hesternus]]'', which vanished along with [[horse]]s, [[Arctodus|short-faced bear]]s, [[mammoth]]s and [[mastodon]]s, [[ground sloth]]s, [[sabertooth cat]]s, and many other megafauna as part of the [[Quaternary extinction event]], coinciding with the migration of humans from Asia at the end of the Pleistocene, around 13–11,000 years ago.<ref name=worboys10>{{cite book | publisher = Earthscan | isbn = 9781844076048 | last1 = Worboys | first1 = Graeme L. | first2 = Wendy L.|last2= Francis|first3= Michael |last3=Lockwood | title = Connectivity Conservation Management: A Global Guide | date = 30 March 2010 |page=142}}</ref><ref name=macphee99>{{cite book | publisher = Springer | isbn = 9780306460920 | last1 = MacPhee | first1 = Ross D. E. | first2 = Hans-Dieter |last2=Sues | title = Extinctions in Near Time: Causes, Contexts, and Consequences | date = 30 June 1999 |pages=18, 20, 26}}</ref>

An extinct giant camel species, ''[[Camelus knoblochi]]'' roamed Asia during the Late Pleistocene, before becoming extinct around 20,000 years ago.<ref name=":0">{{Cite journal |last1=Yuan |first1=Junxia |last2=Hu |first2=Jiaming |last3=Liu |first3=Wenhui |last4=Chen |first4=Shungang |last5=Zhang |first5=Fengli |last6=Wang |first6=Siren |last7=Zhang |first7=Zhen |last8=Wang |first8=Linying |last9=Xiao |first9=Bo |last10=Li |first10=Fuqiang |last11=Hofreiter |first11=Michael |last12=Lai |first12=Xulong |last13=Westbury |first13=Michael V. |last14=Sheng |first14=Guilian |date=May 2024 |title=Camelus knoblochi genome reveals the complex evolutionary history of Old World camels |url=https://linkinghub.elsevier.com/retrieve/pii/S0960982224005244 |journal=Current Biology |volume=34 |issue=11 |pages=2502–2508.e5 |language=en |doi=10.1016/j.cub.2024.04.050|pmid=38754423 |bibcode=2024CBio...34.2502Y |url-access=subscription }}</ref>

<gallery mode="packed" heights="150">
File:Stenomylus.jpg|alt=A drawing of two early camels|[[Stenomylus]] illustration
File:NMNH-USNMV16601Stenomylus.tif|[[Stenomylus]] skeleton
File:NMNH-USNMV15917Poebrotherium.jpg|[[Poebrotherium]] skeleton
File:NMNH-USNM244271 2.jpg|[[Procamelus]] skull
File:Camelops hesternus.jpg|alt=|''[[Camelops hesternus]]'', the last true camel native to North America
</gallery>