作者:NhaYen Nguyen 11 年以前
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Peripheral Isolate Model: An isolate population emerges on the peripheral edge of the ancestral population.
Dumbell Model: The population is divided in half by a geographic barrier.
The genus Homo evolved 2 MYA. Homo habilis existed 2 - 1.8 MYA but went extinct. Homo erectus existed 1 MYA and evolved into Homo sapien, whiched evolved 350,000 MYA.
The more advanced hominid was Australopithecus (5 MYA)
The oldest hominid was Ardipithecus (6.5 MYA)
Low latitude species have smaller ranges than high latitude species.
Insufficient resources and living space, disease, predation, competition, adverse weather conditions.
Rate of reproduction, ability to withstand adverse weather conditions, defense mechanisms.
Natural Selection consistently causes adaptive evolution.
Stabilizing Selection: Removes the extreme variants from the population and preserves tbe intermediate types.
Directional Selection: Shifts the overall makeup of the population by favoring varients that are at the extremes of the population.
-No mutation, no migration, a very large population, random mating, and no selection.
Allele frequency = gene frequency = gamete frequency