Whаt hаs trаditiоnally been cоnsidered tо be the biggest source of people's political values and beliefs?
Reаd the оverview аnd аnswer questiоns 3 and 4. Histоry's Role It’s obvious that different groups of people have differing degrees of skin pigmentation. One proposed explanation for this variability suggests that as our distant, and darker-skinned ancestors left the direct sun of Africa and migrated into northern climates, their sun exposure decreased. This was a problem because the UV light absorbed by our skin is needed to convert the vitamin D from our food into a biologically active form our bodies can use. The decreased sun exposure led to a serious deficit in vitamin D in people living further from the equator. Thus, it became evolutionarily advantageous for those in northern climates to have reduced melanin in their skin in order to increase UV absorption and maximize conversion of vitamin D. Julie’s recent family tree is composed solely of northern Europeans and her degree of skin pigmentation reflects this. She gets more sun exposure than her Irish fore-bearers and therefore the reduced melanin content of her skin makes her especially vulnerable to UV induced skin malignancies. 3) Light-skinned people are at greatest risk for malignant melanoma because _____.