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4 Responses to “Is body hair a form of evolution? How about tails on humans?”
Spina bifida is a birth defect. Basically it’s a failure of the neural tube to close during development, leading to an incomplete spinal cord. I’ve never heard of this having much to do with evolution.
Body hair, on the other hand, is a fantastic example of evolution. The body hair (or pelage) of a mammal is usually an adaptation to its lifestyle: camouflage patterns on large cats and their prey, soft omnidirectional fur on moles, almost no hair on cetaceans to reduce drage, etc. Body hair on humans if often thought to be a result of both sexual selection and natural selection.
Human tails are another good example of how evolution can change morphology. Tails in humans are vestigial–greatly reduced because of a lack of pressure to retain the structure–like the appendix and the wisdom teeth. Since there is no selective pressure against the tail, and some of the gluteal muscles attach to the coccyx, it’s likely to remain a vestigial character for a very long time.
January 24th, 2010 at 6:20 am
Marlee
yes, through evolution lengths and types of hair is changed, and you can see this change through evolution
January 26th, 2010 at 12:00 pm
Jamel
ummm humans w/ tails…. i hav yet to see one of those…
January 29th, 2010 at 9:59 am
Phillip
i think so about the body hair thing. we all have tail bones though, but they just stopped growing
January 29th, 2010 at 6:25 pm
Esmeralda
Spina bifida is a birth defect. Basically it’s a failure of the neural tube to close during development, leading to an incomplete spinal cord. I’ve never heard of this having much to do with evolution.
Body hair, on the other hand, is a fantastic example of evolution. The body hair (or pelage) of a mammal is usually an adaptation to its lifestyle: camouflage patterns on large cats and their prey, soft omnidirectional fur on moles, almost no hair on cetaceans to reduce drage, etc. Body hair on humans if often thought to be a result of both sexual selection and natural selection.
Human tails are another good example of how evolution can change morphology. Tails in humans are vestigial–greatly reduced because of a lack of pressure to retain the structure–like the appendix and the wisdom teeth. Since there is no selective pressure against the tail, and some of the gluteal muscles attach to the coccyx, it’s likely to remain a vestigial character for a very long time.