genomics presentation

genomics presentation - Courtney Peterson BAA 180S...

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Courtney Peterson BAA 180S – Ape/Human Transition *Sorry that I had to go past two pages, I just love my genomes Genomics The aim of this lesson was to provide the class with a brief introduction to the role of genomics within the field of biological anthropology. The lesson began with differentiating genetics and genomics: genetics primarily concerns the realm of genetic inheritance, that is, the past and the future, whereas genomics very much deals with how an individual organism’s genome affects various aspects of its life. As with all sciences, however, genomics does not occur within a vacuum, and the environment has been shown to have impacts on an organism that cannot otherwise be explained simply through genomics…yet. Genomics and genetics are not mutually exclusive, however; as genomics as well as genetics become more well understood, the two are beginning to overlap more and more. First on the agenda for discussion was the article about lice and comparing the genomic differences between body (i.e. clothing) lice on humans and other lice that prefer true hair. Because the former species of lice is presumed to have emerged only after humans lost their hair and began to wear clothing, the genomic differences between the two can be used as a sort of clock, given that the genome accumulates mutations at a rather predictable rate. This kind of analysis predicts a date of hair loss to be just over one hundred million years ago, which is relatively recent given that the human-chimp split has been genomically calculated to be about five to six million years ago. There are many implications for losing body hair. These implications include but are not limited to the use of clothing, increased activity of sweat glands, and melanocytes. Melanocytes in particular have been of interest in the environmental affects of UV radiation in humans. Assuming the Out of Africa theory is more or less true (which genomics has lent support to through mitochondrial and Y-chromosome DNA analysis), as humans radiated, selective pressure was placed on the portions of the genome controlling expression of melanocytes, which produce pigment that protects the DNA from the sun’s damaging UV rays. The skin is not predisposed to a specific skin tone but rather a range of skin tones that is environmentally determined as an individual is exposed to sunlight. Too little protection from the sun increases the risk of pre-mature skin cancer, which would presumably reduce reproductive fitness, and too
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genomics presentation - Courtney Peterson BAA 180S...

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