BIO 1300 Lecture 8: Evolution of Hairlessness Part 1
11 Feb 2017
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Document Summary
Among primate cousins we are the only ones who lost a significant portion of their hair. Thermoregulatory tool was likely used by the earliest animals while moving about at night while dinosaurs were less active. Hair acted as an extra layer of protection even against parasites. Hair can be used to express a message or emotion. The hippo and elephant likely lost hair to keep themselves cool in their hot. Any mammals that don"t have hair evolved the loss and don"t need hair to stay warm environments; due to their size there body acts as insulation itself. They have a low surface area to volume ratio. They have difficulty diffusing heat out of their bodies compared to a smaller animal of similar shape. Naked mole rats live entirely underground; hair is not needed and would cause dirt to stick to them. They also live in a relatively constant temperature.
