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To: AndrewC
[In the case of Wisdom teeth, which we DO NOT need, and some humans are indeed borm without them, this in fact proves evolution. Because if it is not needed, it is dropped from the genetic code because it is NO longer necessary for survival, just as the appendix, and one other organ that I can't remember right now. If they are removed, you will survive just fine without them.]

Wow! You need to meet the genetic drift theorists.

Wow! You need to learn more about genetic drift.

Genetic drift applies when a trait is both a) not genetically linked to other traits and b) strictly neutral to selection.

That's not the case for wisdom teeth.

158 posted on 02/20/2003 10:22:07 PM PST by Ichneumon
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To: Ichneumon
Genetic drift applies when a trait is both a) not genetically linked to other traits and b) strictly neutral to selection.

That's not the case for wisdom teeth.

Nice try at a tap dance, but your statement was a general one. if it is not needed, it is dropped from the genetic code because it is NO longer necessary for survival, just as the appendix...

Anyway your favorite place has this to say about drift

Suzuki et al. explain it as well as anyone I've seen;

"If a population is finite in size (as all populations are) and if a given pair of parents have only a small number of offspring, then even in the absence of all selective forces, the frequency of a gene will not be exactly reproduced in the next generation because of sampling error. If in a population of 1000 individuals the frequency of "a" is 0.5 in one generation, then it may by chance be 0.493 or 0.0505 in the next generation because of the chance production of a few more or less progeny of each genotype. In the second generation, there is another sampling error based on the new gene frequency, so the frequency of "a" may go from 0.0505 to 0.501 or back to 0.498. This process of random fluctuation continues generation after generation, with no force pushing the frequency back to its initial state because the population has no "genetic memory" of its state many generations ago. Each generation is an independent event. The final result of this random change in allele frequency is that the population eventually drifts to p=1 or p=0. After this point, no further change is possible; the population has become homozygous. A different population, isolated from the first, also undergoes this random genetic drift, but it may become homozygous for allele "A", whereas the first population has become homozygous for allele "a". As time goes on, isolated populations diverge from each other, each losing heterozygosity. The variation originally present within populations now appears as variation between populations." (Suzuki, D.T., Griffiths, A.J.F., Miller, J.H. and Lewontin, R.C. in An Introduction to Genetic Analysis 4th ed. W.H. Freeman 1989 p.704)

160 posted on 02/20/2003 10:34:13 PM PST by AndrewC (If an argument doesn't work, Darwininians will coopt the opposite argument)
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