Editing Allen's rule (section)

==In humans==
[[File:Eskimo group - NARA - 523819.jpg|thumb|[[Eskimo]] Group by photographer [[William Dinwiddie]] (1894)]]

Marked differences in limb lengths have been observed when different portions of a given human population reside at different altitudes. Environments at higher altitudes generally experience lower ambient temperatures. In [[Peru]], individuals who lived at higher elevations tended to have shorter limbs, whereas those from the same population who inhabited the more low-lying coastal areas generally had longer limbs and larger trunks.<ref>{{cite journal |first=Karen J. |last=Weinstein |title=Body Proportions in Ancient Andeans from High and Low Altitudes |journal=American Journal of Physical Anthropology |date=November 2005 |volume=128 |issue=3 |pages=569–585 |doi=10.1002/ajpa.20137 |pmid=15895419}}</ref>

Katzmarzyk and Leonard similarly noted that human populations appear to follow the predictions of Allen's rule.<ref name="Katzmarzyk and Leonard"/><sup>:494</sup> There is a negative association between [[body mass index]] and mean annual temperature for indigenous human populations,<ref name="Katzmarzyk and Leonard"/><sup>:490</sup> meaning that people who originate from colder regions have a heavier build for their height and people who originate from warmer regions have a lighter build for their height. Relative sitting height is also negatively correlated with temperature for [[Indigenous peoples|indigenous]] human [[Population|populations]],<ref name="Katzmarzyk and Leonard"/><sup>:487–88</sup> meaning that people who originate from colder regions have proportionally shorter legs for their height and people who originate from warmer regions have proportionally longer legs for their height.<ref name="Katzmarzyk and Leonard">{{cite journal |last1=Katzmarzyk |first1=Peter T. |last2=Leonard |first2=William R. |date=1998 |title=Climatic Influences on Human Body Size and Proportions: Ecological Adaptations and Secular Trends |journal=American Journal of Physical Anthropology |volume=106 |issue=4 |pages=483–503 |doi=10.1002/(SICI)1096-8644(199808)106:4<483::AID-AJPA4>3.0.CO;2-K |pmid=9712477}}</ref>
[[File:Mean annual temperature and brachial index in selected modern populations.jpg|thumb|Mean annual temperature and limb proportions in selected modern populations.]]
In 1968, A.T. Steegman investigated the assumption that Allen's rule caused the structural configuration of the face of human populations adapted to polar climate. Steegman did an experiment that involved the survival of rats in the cold. Steegman said that the rats with narrow [[Nasal passage|nasal]] passages, broader faces, shorter tails and shorter legs survived the best in the cold. Steegman said that the experimental results had similarities with the Arctic Mongoloids, particularly the [[Eskimo]] and [[Aleut]], because these have similar [[Morphology (biology)|morphological]] features in accordance with Allen's rule: a narrow nasal passage, relatively large heads, long to round heads, large jaws, relatively large bodies, and short limbs.<ref>{{cite journal |last1=Steegmann |first1=A.T. |last2=Platner |first2=W.S. |date=January 1968 |title=Experimental cold modification of cranio-facial morphology |journal=American Journal of Physical Anthropology |volume=28 |issue=1 |pages=17–30 |doi=10.1002/ajpa.1330280111 |pmid=5659959 }}</ref>

Allen's rule may have also resulted in wide noses and alveolar and/or maxillary prognathism being more common in human populations in warmer regions, and the opposite in colder regions.<ref>{{Cite web |last=Rae |first=Todd C. |last2=Koppe |first2=Thomas |last3=Stringer |first3=Chris B. |date=27 October 2010 |title=The Neanderthal face is not cold adapted |url=https://edisciplinas.usp.br/pluginfile.php/6200375/mod_resource/content/1/The%20neanderthal%20face%20is%20not%20cold%20adapted%20%28Rae%20et%20al%202011%29.pdf |access-date=5 May 2024 |website=Moodle USP: e-Disciplinas}}</ref>