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qetzal



Posts: 308
Joined: Feb. 2006

(Permalink) Posted: Nov. 11 2011,11:26   

I hope you'll pardon me for jumping into an ongoing discussion.

 
Quote (Southstar @ Nov. 11 2011,08:56)
Okay I get it but supposing we do some tests on generations of Drosophila, cause they're quite easy to breed and we can do a nice time lap test on them.

But instead of doing it out in the open we do it in in a lab, where the happy flies have really eveything they need. Esentially what we are doing here is eliminating natural selection.


Actually, no. You'd just be changing the selective pressures, because you've altered the environment. Any genotype/phenotype that gave a fly an advantage in this new lab environment would still be selectable (and selected). You could argue that it's artificial (human-caused) selection instead of natural selection, but that's really just semantics.

Quote (Southstar @ Nov. 11 2011,10:09)
What it boils down to is that, in the absense of natural selection, do speices evolve randomly.


Yes. It's called genetic drift. Even when there's no selective pressure at all, a certain fraction of new mutations will get fixed in a population over a given period of time. Depends on breeding population size and mutation rate.

  
  366 replies since Nov. 08 2011,06:46 < Next Oldest | Next Newest >  

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