Why do African people have longer limbs?

W.O.W. I have always wondered, why do African people have longer arms and legs. I typed the question in google and voila. There is a scientific explanation for it : Allen's rule.

Allen's rule

Nature never failed to amaze me.

Quote:

In cold climates, the greater the exposed surface area, the greater the loss of heat and therefore energy. Animals in cold climates need to conserve as much energy as possible. A low surface area to volume ratio helps to conserve heat.

In warm climates, the opposite is true. An animal will overheat quickly if it has a low surface area to volume ratio. Therefore, animals in warm climates will have high surface area to volume ratios so as to help them lose heat.

In a nutshell, it simply means there is a ratio between body surface to body mass. For example, Fur or Tutsi people of Africa release body heat more readily because their ratio is high. However, Eskimos and Inuit have a lower ratio and therefore retain body heat.

The Inuit people live and hunt within the Arctic Circle. The sub-zero temperatures encountered in the Arctic environment mean that heat conservation is essential. A short, squat body shape will help retain body heat.

The Maasai people live primarily in Kenya and north Tanzania. The equatorial temperatures in this environment mean that heat loss is highly beneficial. A tall, long, body shape will help get rid of body heat. (The use of the word "tall" here is somewhat misleading. It is not necessarily height that is a factor as it is relatively longer, leaner limbs and a lean frame which are most appropriate according to this rule. Basically, size is not the main factor, which would be Bergmann's Rule, but shape.)

Unquote.