Gloger's rule

Gloger's rule

Gloger's Rule is a zoological rule which states that within a species of endotherms, more heavily pigmented forms tend to be found in more humid environments, e.g. near the equator. It was named after the zoologist Constantin Wilhelm Lambert Gloger, who first remarked upon this phenomenon in 1833 in a review of covariation of climate and avian plumage color. [Gloger (1833)] Gloger found out that birds in more humid habitat tended to be darker than their relatives from regions with higher aridity. Over 90% of the species researched conform to this rule.Fact|date=February 2007

An explanation of Gloger's rule in the case of birds appears to be the increased resilience of dark feathers to feather (and hair-degrading) bacteria (such as "Bacillus licheniformis"). Feathers in humid environments have a greater bacterial load and humid environments are more suitable for microbial growth, but dark feathers or hair are more difficult to break down. [Burtt & Ichida (2004)] More resilient eumelanins - dark brown to black - are deposited in hot and humid regions, whereas in arid regions, pheomelanins - reddish to sandy color - predominate due to the benefit of crypsis.

Among mammals, there is a marked tendency in equatorial and tropical regions to have a darker skin color than poleward relatives. In this case, the underlying cause is probably the need to better utilize the sun's UV radiation with decreasing latitude. Absorption of a certain amount of UV radiation is necessary for the production of certain vitamins, notably Vitamin D ("see also" Osteomalacia).

This principle is also vividly demonstrated amongst human populations. [Ember "et al." (2002)] Populations that evolved in sunnier environments closer to the equator tend to be darker pigmented than populations originating farther from the equator. There are exceptions, however; among the most well-known are the Tibetans and Inuit, who have darker skin than might be expected from the latitude at which they evolved. In the first case, this is apparently an adaptation to the extremely high UV irradiation on the Tibetan Plateau, whereas in the second case, the necessity to absorb UV radiation is alleviated by a diet that is naturally rich in Vitamin D.

ee also

*Allen's rule
*Bergmann's Rule

Footnotes

References

* (2004): Gloger's Rule, feather-degrading bacteria, and color variation among Song Sparrows. "Condor" 106(3): 681-686. doi|10.1650/7383 [http://www.public.asu.edu/~kjmcgraw/pubs/Condor04b.pdf PDF fulltext]
* (2002): "Anthropology" (10th ed.). Prentice Hall.
* (1833): "Das Abändern der Vögel durch Einfluss des Klimas". August Schulz, Breslau. de icon


Wikimedia Foundation. 2010.

Игры ⚽ Нужна курсовая?

Look at other dictionaries:

  • Gloger’s rule — Gloger’s rule. См. правило Глогера. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • Gloger's rule — /ˈgloʊgəz rul/ (say glohguhz roohl) noun the rule which states that warm blooded animals of the same species are more heavily pigmented in more humid environments. {posited in 1833 by Constantin Wilhelm Lambert Gloger, 1803–63, German zoologist} …  

  • gloger's rule — ˈglōgə(r)z noun Usage: usually capitalized G Etymology: after C. W. L. Gloger died 1863 German zoologist : a statement in zoology: within a species of warm blooded animals the degree of melanin pigmentation tends to vary directly with the mean… …   Useful english dictionary

  • Regle de Gloger — Règle de Gloger La règle de Gloger est une règle empirique de répartition au sein des espèces animales homéotherme (à sang chaud) en fonction de leur pigmentation et de l hygrométrie locale. Le zoologiste Constantin Wilhelm Lambert Gloger (1803… …   Wikipédia en Français

  • Règle de gloger — La règle de Gloger est une règle empirique de répartition au sein des espèces animales homéotherme (à sang chaud) en fonction de leur pigmentation et de l hygrométrie locale. Le zoologiste Constantin Wilhelm Lambert Gloger (1803 1863) constata en …   Wikipédia en Français

  • Constantin Wilhelm Lambert Gloger — (1803 near Grottkau, Silesia, Kingdom of Prussia–1863 in Berlin) was a German zoologist and ornithologist. Gloger was the first person to recognise the structural differences between swallows and swifts, and also the first to put up artificial… …   Wikipedia

  • Règle de Gloger — La règle de Gloger est une règle empirique de répartition au sein des espèces animales homéotherme (à sang chaud) en fonction de leur pigmentation et de l hygrométrie locale. Le zoologiste Constantin Wilhelm Lambert Gloger (1803 1863) constata en …   Wikipédia en Français

  • Cope's rule — states that population lineages tend to increase in body size over evolutionary time.[1] While the rule has been demonstrated in many instances, it does not hold true at all taxonomic levels, or in all clades. Larger body size is associated with… …   Wikipedia

  • Bergmann's Rule — In zoology, Bergmann s rule is an ecogeographic rule that correlates latitude with body mass in animals.Tim M. Blackburn; Kevin J. Gaston; Natasha Loder (1999) Geographic Gradients in Body Size: A Clarification of Bergmann s Rule Diversity and… …   Wikipedia

  • Allen's rule — is a biological rule posited by Joel Asaph Allen in 1877. It states that endotherms from colder climates usually have shorter limbs (or appendages) than the equivalent animals from warmer climates. Theory The theory behind Allen s Rule is that… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”