On Wed, 7 Apr 2004 16:38:55 +0000 (UTC), Anon. 
 wrote:

[snip]

> How can you get drift with Ne=infinity?  We've thought about it, and 
> some have even bee into the field and sampled midlew.  It's diverse, and 
> there's a lot of it about, so Ne=infinity is a good approximation.  I 
> think my point is that any null hypothesis has to be referenced to the 
> species and population you're studying.
> 
> Of course, there are other stochastic events - founder effects and 
> bottlenecks, and these can occur (and indeed probably do have a 
> significant effect on the populations).

Random genetic drift is the process of change in allele frequency
due solely to chance. It includes founder effects and bottlenecks.
You may have been assuming that trandom genetic drift was only due
to sampling effects during sexual reproduction.

I assume someone has sampled mildew for heterozygosity? If so, I assume
that the local population contains a large number of alleles of 
different genes. How did this happen? Are all of these alleles examples
that are in the process of becoming fixed or eliminated by natural 
selection?

I assume that someone has sampled mildew from different parts of the
country? Is the frequency of alleles identical in these samples?
Why not?

In evolutionary terms, a true population is a group of individuals 
where every individual has an equal chance of mating with every
other individual. The term for this is "panmitic." Most species consist
of many populations where gene flow is restricted in one way or 
another. I doubt very much whether the effective population size
of mildew is anywhere near infinity. Aren't mildew species usually
sub-divided into sub-species and isolates?




Larry Moran
---
þ RIMEGate(tm)/RGXPost V1.14 at BBSWORLD * Info{at}bbsworld.com

---
 * RIMEGate(tm)V10.2áÿ* RelayNet(tm) NNTP Gateway * MoonDog BBS
 * RgateImp.MoonDog.BBS at 4/8/04 6:44:37 AM