[Taxacom] Early angiosperms (and hymenopteran co-evolution)

[John Grehan]

-----Original Message-----
From: taxacom-bounces at mailman.nhm.ku.edu
[mailto:taxacom-bounces at mailman.nhm.ku.edu] On Behalf Of Kenneth Kinman
Sent: Saturday, March 20, 2010 10:57 PM
To: taxacom at mailman.nhm.ku.edu
Subject: [Taxacom] Early angiosperms (and hymenopteran co-evolution)

>Dear All,      
>      Well, as far as Croizat is concerned, the value of his input on
this 
> particular issue will ultimately rest on whether early angiosperms
evolved in very
> wet environments (mangroves) or rather dry, upland environments.  He
may have 
> gotten the right answer for the wrong reason, in which case he doesn't
deserve the 
> credit that should be given those who got the right answer for the
RIGHT reason. 
> We shall see.      

Sounds a bit like sophistry to me.
                     
>      Either way, I strongly suspect that the drastic and widespread
nature of the 
> end-Permian extinction had a profound effect in initiating the
beginnings of the
> rise of angiosperms over their gymnosperm ancestors.  

Looks like you have been reading Croizat on the sly.

> If so, their early Mesozoic proliferation is similar to (but not quite
as sudden 
> as) the more rapid Cenozoic proliferation of mammals and birds over
their reptile 
> ancestors following the end-Cretaceous extinction.  But as has been
noted, a 
> restricted upland habitat of Triassic (and/or earlier) angiosperms may
have simply
> been unfavorable to fossil preservation, 

Or it may not have existed at all.

John Grehan

although I am not sure this is quite as 
> valid for pollen preservation unless early angiosperms were very
dependent on 
> insect pollination rather than more widespread pollination by wind
dispersal.   

      That is where the early co-evolution of angiosperms and certain
insect taxa becomes particularly relevant.  The evolution of Hymenoptera
in particular seems to be rather intimately associated with angiosperms
(and perhaps the wasps in particular, since they are the equivalent of
the "reptiles" of the hymenopterans).  Of course, this may have
initially been clouded by equally important interactions with early
beetles (or even forms intermediate between beetles and early
hymenopterans).
          ---------Ken Kinman


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