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why Australian Aborigenes have straight hair
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[QUOTE]Originally posted by AGÜEYBANÁ(Mind718): [QB] Why don't you actually read what Jablosnki has to say about it instead of acting like you did, which from your time here and responses you obviously didn't. See here... [QUOTE]Nina G. Jablonski and George Chaplin 2000 [i]The evolution of human skin coloration Skin color is one of the most conspicuous ways in which humans vary and has been widely used to define human races. Here we present new evidence indicating that variations in skin color are adaptive, and are related to the regulation of ultraviolet (UV) radiation penetration in the integument and its direct and indirect effects on fitness. Using remotely sensed data on UV radiation levels, hypotheses concerning the distribution of the skin colors of indigenous peoples relative to UV levels were tested quantitatively in this study for the first time. The major results of this study are: [b](1)[/b] skin reflectance is strongly correlated with absolute latitude and UV radiation levels. The highest correlation between skin reflectance and UV levels was observed at 545 nm, near the absorption maximum for oxyhemoglobin, suggesting that the main role of melanin pigmentation in humans is regulation of the effects of UV radiation on the contents of cutaneous blood vessels located in the dermis. [b](2)[/b] Predicted skin reflectances deviated little from observed values. [b](3)[/b] In all populations for which skin reflectance data were available for males and females, females were found to be lighter skinned than males. [b](4)[/b] The clinal gradation of skin coloration observed among indigenous peoples is correlated with UV radiation levels and represents a compromise solution to the conflicting physiological requirements of photoprotection and vitamin D synthesis.[/i] [/QUOTE]^Seems like you're stuck at one (1) saying "duhhhhh but where do I go now" while Jablosnki and everyone else is already on four (4). [/QB][/QUOTE]
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