Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Skin Color Factors Melanin - Pigment in skin, eyes, hair Carotene - a copper-colored pigment Skin Thickness Reflection of Blood Vessels Skin Color Distribution Why? Natural Selection In Tropics – Reduces frequency of skin cancer – Reduces likelihood of severe sunburn which interferes with sweating – Melanin screens sunlight passing through skin • Regulates Vitamin D Production • Which Regulates deposition of Calcium • Too Much Calcium > Calcification of soft tissues In Higher Latitudes – Too Little Calcium > Rickets; Reduced Size of Birth Canal Lower production of melanin, especially in females of reproductive age, • would be reinforced through differences in reproductive success, and • the genes coding for this variant would be differentially transmitted to offspring. • There are two variants of the gene SLC24A5. • The first variant has a frequency of 99% among European Americans. • The other has a frequency of 93 to 100% among East Asians