ANTH 1001 : Anthropology Exam 2- Notes
Document Summary
Skin pigmentation: pigment in melanin, melanin is produed in melanocytes, which are epidermis of skin, melanin is packaged into granules called melanosomes, melanosomes are transferred to keratinocytes, which are also in epidermis. Genetic similarities between heavily ad lightly melanized individuals: all people have about the same number of melanocytes, compared to lightly melanized individual, heavily melanzied individual, produced more melanosomes, has larger melanosomes, and, melanosomes are more dispersed in keratinocyte. Natural selective advantage to variation in skin pigmentation: dark skin pigmentation is adaptive in areas of intense ultraviolet radiation, melanin functions to absorb uv radiation, reduced likelihood of skin cancer and degradation of folate. Light skin pigmentation is adaptive in areas of low ultraviolet radiation: allows sufficient synthesis of vitamin d, reduces likelihood of rickets. Bergmann"s rule: body mass is higher in areas with lower temperatures. Length of arms and legs is shorter in areas with lower temperatures.
