2006-12-26 15:54:09 · 3 answers · asked by B 3 in Social Science ➔ Anthropology
I am talking about the head index, the ratio, that is over %85.
2006-12-26 16:24:29 · update #1
You mean "BRACHYCEPHALIA." And no, it isn't, unless conditions change to where having down syndrome increases chances for survival and reproduction. That's not going to happen.
2006-12-26 16:06:06 · answer #1 · answered by Anonymous · 1⤊ 0⤋
Ninjalect refers to a concept known as 'neutral evolution'. This is where a trait develops as a characteristic of a population for other reasons, but only becomes advantageous when the environment changes in such a way as to select for that population. A typical example of this would be penicillin resistance in bacteria. In the 1930's only 1 bacteria in millions was resistant to the drug, but now most of the bacteria are resistant. The gene was neutral, but the effect was selected for by the change in environment.
The index you refer to probably was an advantage to our predecessors as tree dwelling mammals who moved to the ground and developed an upright position with a larger brain to process more information. Whether it will become an advantage again or if it will change, remains to be seen in about a million years or so
2006-12-27 10:11:11 · answer #2 · answered by cuban friend 5 · 1⤊ 0⤋
It must be if it's related to as something real,......what is it?
2006-12-27 00:02:54 · answer #3 · answered by Stony 4 · 0⤊ 1⤋