JF, do you understand that ecosystems are made up of species, not phyla? If
you do then I think you can see that the *species* of angiosperms from 90
million years ago are, in most cases, not the *species* of angiosperms of
today. Therefore, the ecosystems, of which these *species* of angiosperms
are a small part, have changed even at the level angiosperems. Did you
follow that? Ecosystems (if such exist) are not made of phyla, they are made
of species. If you or Grant (whoever that is? Which Grant?) are saying that
only changes at the level of phyla are "evolutionary" then I'm lost. Phyla
do not evolve, only species evolve. Why would Grant call his/her book
"Organismic Evoluion" and then make such a claim? Maybe you had better go
back and read that section.
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JF wrote:
Well. I should clarify. After all I was only quoting Grant, from "Organismic
Evolution"; I attempted to claim that the only (or most) significant change
on an evolutionary scale during the last 90 million years was the evolution
of flowering plants, angiosperms. This is just an opinion. Certainly there
are some other changes but these others I believe are due to flowering
plants becoming dominant in many ecosystems. Certainly the existence of
glaciations wroughts change but glaciations began 140 million years or so
ago, and are only one component of environmental change, and does not have a
direct permanent effect on ecosystems, nor species, unless they are forced
to adapt or perish. Climate may influence evolution because in a gradual
changing environment many species may be able to adapt, especially if there
is a polymorphic gene pool.
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Bissell here; Just a question to JF. When you use the term "phyletic" what
are your refering to?
JF wrote:
The item that interests me from a moral perspective is the myriad phyletic
lineages that adapt to and exploit new ecological niches.
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