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jeannot



Posts: 1200
Joined: Jan. 2006

(Permalink) Posted: May 15 2009,09:43   

Quote (Erasmus, FCD @ May 14 2009,21:41)
Quote (jeannot @ May 09 2009,18:49)
This is hardly a breakthrough but we've got a paper published in PNAS this week about speciation, more specifically the blurry frontier between what we may call subspecies and species. Of course, there's no strict boundary, as well as there is no qualitative difference between micro- and macroevolution, if this is relevant to the anti-evolution debate.

The work is done on an aphid species complex. Feel free to give you opinion on this. Full access requires subscription, but I can provide a pdf for those interested.

http://www.pnas.org/content/106/18/7495.abstract

pffft its still an aphid.  wake me up when one turns into a blue whale or summtin.  evilutionists

hey jean i noticed that at least some of those plants are tag-alongs with humans (clover, afalfa, peas, vetch)  i didn't recognize some of the others but i wouldn't.  

wondering if you had any idea of what the ancestral host preference mighta been?  i'm not swift enough to figure out if the biotypes that can switch hosts prefer hosts that have been strongly domesticated.  would make sense that selection for being tasty for people or livestock, if it reduces any defense complexes, might make you tastier for insects.

in one fell swoop you have generated more science than the entire ID movement in 2008 AND 2009.  Cheers!

We don't know the ancestral host. It could be an annual vetch related to broad bean, which is suitable for all biotypes. But we don't have the data to test this.

Artificial selection for/against plant defenses is an interesting question. But pea and broad bean, which do not grow in the wild, are far from being deprived of anti-insect defenses.
In fact, host fidelity seems a bit stronger in some biotypes feeding on wild plants, like broom, restharrow and meadow vetchling. But these biotypes may have diverged more anciently.

  
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