In: Biology
Examples of climate/ geography drives natural selection in humans.
A positive effect of climate or geography on human body may be responsible for evolution of new traits. The trait is inherited from one generation to another generation if it is naturally selected and stable. For example the trait of skin pigmentation. As we all know life is evolve from Africa. A worm place where skin colour is dark having high concentration of melanin. Melanin helps skin from harmful damage of UV rays. It can causes skin cancer. As humans are migrates from Africa to Asia and Europe, they have positive selection effect on their genes. Europe and Asia are colder places as compared to Africa. Hence high concentration of melanin is not required in skin pigmentation. Hence the new trait of white skin with less melanin pigmentation is originated. It will also protect skin from extreme cold too. The trait is inherited from generation after generation and become stable in those population.