Editing Elephant (section)

====Tusks====
The tusks of an elephant are modified second incisors in the upper jaw. They replace deciduous [[milk teeth]] at 6–12 months of age and keep growing at about {{convert|17|cm|in|0|abbr=on}} a year. As the tusk develops, it is topped with smooth, cone-shaped [[tooth enamel|enamel]] that eventually wanes. The [[dentin]]e is known as [[ivory]] and has a [[Cross section (geometry)|cross-section]] of intersecting lines, known as "engine turning", which create diamond-shaped patterns. Being living tissue, tusks are fairly soft and about as dense as the mineral [[calcite]]. The tusk protrudes from a socket in the skull, and most of it is external. At least one-third of the tusk contains the [[Pulp (tooth)|pulp]], and some have nerves that stretch even further. Thus, it would be difficult to remove it without harming the animal. When removed, ivory will dry up and crack if not kept cool and wet. Tusks function in digging, debarking, marking, moving objects, and fighting.<ref name=Shoshani71 />

Elephants are usually right- or left-tusked, similar to humans, who are typically [[Handedness|right- or left-handed]]. The dominant, or "master" tusk, is typically more worn down, as it is shorter and blunter. For African elephants, tusks are present in both males and females and are around the same length in both sexes, reaching up to {{convert|300|cm|ftin|0|abbr=on}},<ref name=Shoshani71 /> but those of males tend to be more massive.<ref>Sukumar, p. 120</ref> In the Asian species, only the males have large tusks. Female Asians have very small tusks, or none at all.<ref name=Shoshani71>Shoshani, pp. 71–74.</ref> Tuskless males exist and are particularly common among [[Sri Lankan elephant]]s.<ref>{{cite book|author=Clutton-Brock, J.|year=1986|title=A Natural History of Domesticated Mammals|publisher=British Museum (Natural History)|page=208|isbn=978-0-521-34697-9}}</ref> Asian males can have tusks as long as Africans', but they are usually slimmer and lighter; the largest recorded was {{convert|302|cm|ftin|0|abbr=on}} long and weighed {{convert|39|kg|lb|0|abbr=on}}. Hunting for elephant ivory in Africa<ref>{{cite web|title=Elephants Evolve Smaller Tusks Due to Poaching|date=20 January 2008|publisher=Environmental News Network|url=http://www.enn.com/wildlife/article/29620|access-date=25 September 2012|archive-date=21 November 2015|archive-url=https://web.archive.org/web/20151121185117/http://www.enn.com/wildlife/article/29620|url-status=live}}</ref> and Asia<ref>{{Cite web|date=2018-11-09|title=Under poaching pressure, elephants are evolving to lose their tusks|url=https://www.nationalgeographic.com/animals/article/wildlife-watch-news-tuskless-elephants-behavior-change|url-status=dead|access-date=2021-10-28|website=[[National Geographic]]|language=en|archive-url=https://web.archive.org/web/20210303222242/https://www.nationalgeographic.com/animals/article/wildlife-watch-news-tuskless-elephants-behavior-change/ |archive-date=3 March 2021 }}</ref> has resulted in an effective [[selection pressure]] for shorter tusks<ref>{{cite news|url=https://www.telegraph.co.uk/science/science-news/3322455/Why-elephants-are-not-so-long-in-the-tusk.html|archive-url=https://web.archive.org/web/20091018192954/http://www.telegraph.co.uk/science/science-news/3322455/Why-elephants-are-not-so-long-in-the-tusk.html|url-status=dead|archive-date=18 October 2009|title=Why elephants are not so long in the tusk|last=Gray|first=R.|date=20 January 2008|work=[[The Daily Telegraph]]|access-date=27 January 2013}}</ref><ref>{{cite journal|author1=Chiyo, P. I. |author2=Obanda, V. |author3=Korir, D. K. |title=Illegal tusk harvest and the decline of tusk size in the African elephant|journal=Ecology and Evolution|year=2015|volume=5|issue=22|pages=5216–5229|doi=10.1002/ece3.1769|pmid=30151125|pmc=6102531|bibcode=2015EcoEv...5.5216C }}</ref> and tusklessness.<ref>{{cite journal|author1=Jachmann, H. |author2=Berry, P. S. M. |author3=Imae, H. |year=1995|title=Tusklessness in African elephants: a future trend|journal=African Journal of Ecology|volume=33|issue=3|pages=230–235|doi=10.1111/j.1365-2028.1995.tb00800.x|bibcode=1995AfJEc..33..230J }}</ref><ref>{{cite journal|author1=Kurt, F. |author2=Hartl, G. |author3=Tiedemann, R. |year=1995|title=Tuskless bulls in Asian elephant ''Elephas maximus''. History and population genetics of a man-made phenomenon.|journal=Acta Theriol.|volume=40|pages=125–144|doi=10.4098/at.arch.95-51|doi-access=free}}</ref>