BIOLOGY 1M03 Lecture Notes - Lecture 26: Selective Sweep, Chromosome, Inuit
25 Mar 2017
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Document Summary
Microsatellite: dna diversity (and other genetic data) supports the hypothesized dispersal out of. Genetic variation and natural selection in homo sapiens. Chimps have light skin darkens with age protected by hair ancestors shared with humans likely were light skinned. Skin colour is partly genetic skin colour changes overtime but original is genetic. Factors favouring dark skin in tropics: human skin is almost hairless - cooling through sweating is more e ective melanin protects skin from uva and uvb damage sunburned skin can become infected and cancer prone. Uva breaks down folic acid (folate) adequate folate status necessary for proper dna synthesis, repair and expression folate de ciencies play a negative role in reproductive and developmental processes (neural tube defects, early pregnancy losses among others) Vitamin d3 synthesis/breakdown facilitated by uvb vitamin d3 is made from 7-dehydrocholesterol. 7-dehydro found in keratinocytes of the epidermis, absorbs photons from uvb vitamin d3 production is facilitated by uvb exposure.
