Human Origins

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Biodiversity is the variability of the earth’s species, the genes they contain, the ecosystems in which they live, and the ecosystem processes, such as energy flow and nutrient cycling that sustain all life. (Miller & Spoolman, 2009. pg. 50) It involves many of the levels of organization of life, including genetic diversity species diversity, ecological diversity, and functional diversity. Biodiversity makes up the structure of the ecosystems and habitats that support essential living resources, including wildlife, fisheries and forests. It assists in providing for basic human needs such as food, shelter, and medicine. It composes ecosystems that maintain oxygen in the air, enrich the soil, purify the water, protect against flood and…show more content…
The balance between the two helps explain why people that migrated to colder geographic zones with less sunlight developed lighter skin color. Similarly, as people moved to areas farther from the equator with lower UV levels, natural selection favored lighter skin which allowed UV rays to penetrate and produce essential vitamin D. Additionally, those living in coastal areas, eating diets rich in seafood also receive an alternate source of vitamin D. What this means is that some Arctic people, such as those living in Alaska and some parts of Canada, remained dark-skinned even in low UV areas. (http://humanorigins.si.edu/) How much of the diversity of how people look on the outside is genetically encoded, and how deep are the differences between human groups? Compared to many mammals, humans are genetically less diverse. This finding is contrary to the obvious, given the large population. Early studies of human diversity have shown that most genetic diversity was found between individuals rather than between populations or locations. A study published in 2004 found that 87.6% of the total modern human genetic diversity is accounted for by the differences between individuals, and only 9.2% between continents. (Hinds et al. 2005) The results from the study further
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