Editing Allen's rule (section)

==In animals==

Though there are numerous exceptions, many animal [[Population|populations]] appear to conform to the predictions of Allen's rule. The [[polar bear]] has stocky limbs and very short ears that are in accordance with the predictions of Allen's rule, so does the [[snow leopard]].<ref>{{cite web |first=C. Michael |last=Hogan |date=November 18, 2008 |url=http://www.igoterra.com/artspec_information.asp?thingid=36084 |title=Polar Bear: ''Ursus maritimus'' |website=iGoTerra}}</ref> In 2007, R.L. Nudds and S.A. Oswald studied the exposed lengths of [[seabird]]s' legs and found that the exposed leg lengths were negatively correlated with ''Tm''axdiff (body temperature minus minimum ambient temperature), supporting the predictions of Allen's rule.<ref name="Nudd"/> J.S. Alho and colleagues argued that [[tibia]] and [[femur]] lengths are highest in populations of the [[common frog]] that are indigenous to the middle latitudes, consistent with the predictions of Allen's rule for [[Ectotherm|ectothermic]] [[Organism|organisms]].<ref name="Alho"/> [[Population|Populations]] of the same species from different [[latitude]]s may also follow Allen's rule.<ref>{{cite journal |author-link1=Peter L. Hurd |last1=Hurd |first1=Peter L. |last2=van Anders |first2=Sari M. |date=2007 |title=Letter To The Editor: Latitude, Digit Ratios, and Allen's and Bergmann's Rules: A Comment on Loehlin, McFadden, Medland, and Martin (2006) |journal=Archives of Sexual Behavior |volume=36 |issue=2 |pages=139–141 |doi=10.1007/s10508-006-9149-9|pmid=17333323 |hdl=2027.42/83881 |s2cid=2690330 |url=https://deepblue.lib.umich.edu/bitstream/2027.42/83881/1/latitude_digit_ratios_a_comment_on_loehlin.pdf |hdl-access=free }}</ref>

R.L. Nudds and S.A. Oswald argued in 2007 that there is poor empirical support for Allen's rule, even if it is an "established ecological tenet".<ref name="Nudd"/> They said that the support for Allen's rule mainly draws from studies of single species, since studies of multiple species are "confounded" by the scaling effects of [[Bergmann's rule]] and alternative adaptations that counter the [[Prediction|predictions]] of Allen's rule.<ref name="Nudd">{{cite journal |last1=Nudds |first1=R.L. |last2=Oswald |first2=S.A. |title=An Interspecific Test of Allen's Rule: Evolutionary Implications for Endothermic Species |journal=Evolution |date=December 2007 |volume=61 |issue=12 |pages=2839–2848 |doi=10.1111/j.1558-5646.2007.00242.x |pmid=17941837|s2cid=28694340 |doi-access=free }}</ref>

J.S. Alho and colleagues argued in 2011 that, although Allen's rule was originally formulated for [[endotherm]]s, it can also be applied to [[ectotherm]]s, which derive body temperature from the environment. In their view, ectotherms with lower surface area-to-volume ratios would heat up and cool down more slowly, and this resistance to temperature change might be adaptive in "thermally heterogeneous environments". Alho said that there has been a renewed interest in Allen's rule due to global warming and the "[[Microevolution|microevolutionary]] changes" that are predicted by the rule.<ref name="Alho">{{cite journal |last1=Alho |first1=J. S. |last2=Herczeg |first2=G. |last3=Laugen |first3=A. |display-authors=etal |date=2011 |title=Allen's Rule Revisited: Quantitative Genetics of Extremity Length in the Common Frog Along a Latitudinal Gradient |journal=Journal of Evolutionary Biology |volume=24 |issue=1 |pages=59–70 |doi=10.1111/j.1420-9101.2010.02141.x |pmid=20964781 |s2cid=32746448 |doi-access=free }}</ref>