2007-11-03 14:13:42 · 6 answers · asked by John P 2 in Science & Mathematics ➔ Biology
Fingernails protect our fingertips from injury, and we use our fingernails as tools.
Hair guards our scalps from sunburn and keeps our heads warmer in chilly weather. Our hairier ancestors made better use of the warming effect!
2007-11-03 14:18:35 · answer #1 · answered by ecolink 7 · 3⤊ 0⤋
We don't really, anymore. With the advent of technology, a person without hair could simply wear a hat, and someone without fingernails can use tools to compensate (I'm a nail-biter, and I get along just fine).
Long ago, we needed the hair to keep warm, and the fingernails to dig, cut, fight, etc, but that is no longer the case.
Given enough time and a constant environment similar to the current one, those traits could evolve out completely. It would be hindered by social selection, since bald guys or girls might have a harder time finding someone with whom to have children. Also, the current lack of selection could disappear if civilization collapsed (i.e. nuclear war) and hairy long-nailed people were at an advantage again (in which case, the trend might reverse, and people might evolve to have more hair).
2007-11-04 14:41:38 · answer #2 · answered by andymanec 7 · 0⤊ 0⤋
fingernails procect the fingers. they were also probably used by primitive humans to dig, scratch, and as a tool almost. Hair protects your head from the sun.
2007-11-03 21:20:22 · answer #3 · answered by Lindsey S 2 · 1⤊ 1⤋
hair grows where ever the body wants to be protected
2007-11-03 21:48:43 · answer #4 · answered by timmygrammer 2 · 0⤊ 1⤋
Originally, for survival.
2007-11-03 21:18:48 · answer #5 · answered by belizeable 4 · 1⤊ 1⤋
fingernails-to scratch people when in a catfight
hair-to pull when in a catfight
2007-11-03 21:21:22 · answer #6 · answered by Anonymous · 0⤊ 3⤋