[asa] Definition of "evolution"

I've been listening to the audio CD's of Barbara King teaching her course on Biological Anthropology. She is an excellent lecturer. This morning I noted a few of her comments that may be of interest here.

She defines "evolution" to mean "change in the genetic structure of a population." She says that a "population" is the focus of evolution rather than species. Population is defined as a group of individuals among which reproduction is probable whereas a species is a group of individuals among which reproduction is theoretically possible. That is, a population is a group of individuals who will typically, though not exclusively, select mates from within that population. She notes the BIDE principle. Birth and Immigration are the ways to join a population and Death and Emigration are the ways to leave the population.

She also says that "survival of the fittest" is an erroneous concept and unfortunate phrase. She and her colleagues refer to differential reproductive success (RS) as a more accurate concept.

She notes four critical factors in evolution: natural selection, mutations, gene flow, and gene drift. If I understood her correctly, gene flow is due to the influence of immigration/emigration. Gene drift is due to neutral mutations with no selection pressure. In addition, she emphasizes the importance of environmental factors in influencing the way in which genetic structure is expressed.

It promises to be an informative course.

Randy

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Received on Wed Jun 4 12:20:06 2008