ANTH 225 Lecture Notes - Lecture 5: Sexual Selection, Medium Ground Finch, Sickle-Cell Disease
25 Oct 2016
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Document Summary
To recognize the mechanism by which evolution operated. In each generation, more individuals are produced than can survive. Individuals that possess favorable traits or variations are more likely to survive and produce offspring. Environmental contexts determines whether a trait is beneficial. Traits are inherited and passed on to the next generation. Variations accumulate over long periods of time, so later generations become distinct from ancestral ones. Adaptation: a series of beneficial adjustments to an environment. Evolution occurs when genetic variants in the gene pool of a population change in frequency. Evolution is not survival of the fittest; rather, deletion of the unfit. In 1977 a drought killed plants producing small, soft seeds. Finches capable of feeding on larger, harder seeds survived better. Rains in 1982 and the drought ended, population readjusted. Certain alleles code for higher oxygen saturation in tibetan women. Those with the alleles for higher oxygen transport have.
