Re: Gould criticism and reviews

John Harshman wrote:
Tim Tyler wrote:
John Harshman wrote:

But we can start with the idea that living fossils are relevant
to stasis and PE. What makes you think so? What in fact is your understanding of the claims made by the PE theory?

So you have /still/ have no coherent criticsm of anything I
have said - and are instead hoping that I will make some
misstep in comments which you might provoke me making in
the future. Not a very impressive argument you have there.

It may not be impressive, but you haven't responded to it.

I'm not clear about what I supposedly haven't responded to.

I repeat my claim that "living fossils" have nothing to do with PE.

I repeat my reply that living fossils:

"are an instance of equilibrium in evolution."

That's the same "equilibrium" as in "punctuated equilibrium".

PE is a theory about stasis *of species*, in which morphological
change is coincident with speciation. If crocodiles look rather like
other species of crocodiles did 300 million years ago, that has
nothing to do with PE or stasis.

Living fossils are an example of stasis, just as I claimed.

You raise the issue that living fossils may not necessarily
represent unique species - but if lineages have remained
morphologically unchanged over many millions of years, then
they have also remained morphologically unchanged over
thousands of years - or over whatever timescale you happen
to think species exist over.

You raise the issue that some living fossils represent
clades, rather than individual lineages. That is true
for some living fossils - but not for all of them.
For example, the ginkgo has had no close relatives
since the the Paleocene era.

It seems to me that you are not even /attempting/ a
sympathetic reading - and are instead just looking
for problems, to retrospectivly support your hastily-
jumped-to conclusion that I misunderstood something.

Have you ever actually read any of the technical literature on PE, particularly Eldredge and Gould 1972, the first publication on the subject?

Um, yes.

That is where they invented - and then trashed - "phyletic gradualism".
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Relevant Pages

  • Re: Gould criticism and reviews
    ... If a lineage changes less than that, it's stasis. ... Stasis in the context of PE, which is what we're presumably discussing, is within species. ... Then living fossils are not relevant to it, which is the nub of my argument with you. ... No, it's one explanation for stasis, and your suggested form of stabilizing selection is only one among many explanations that incorporate stabilizing selection, not to mention those that don't. ...
    (talk.origins)
  • Re: Gould criticism and reviews
    ... Living fossils are generally different enough from the fossil species they're compared to that they are considered different species. ... PE is about stasis *within* a single morphospecies. ... But this is not true for coelacanths or for most living fossils -- they are not the same morphospecies as the fossil species. ...
    (talk.origins)
  • Re: Gould criticism and reviews
    ... If a lineage changes less than that, it's stasis. ... Stasis in the context of PE, which is what we're presumably discussing, is within species. ... Then living fossils are not relevant to it, which is the nub of my argument with you. ... Hmmm...you seem to be assuming a form of phyletic gradualism here. ...
    (talk.origins)
  • Re: Gould criticism and reviews
    ... If a lineage changes less than that, it's stasis. ... Stasis in the context of PE, which is what we're presumably discussing, is within species. ... Then living fossils are not relevant to it, which is the nub of my argument with you. ... PE has nothing to say about taxa being at rest on adaptive peaks. ...
    (talk.origins)
  • Re: Gould criticism and reviews
    ... If a lineage changes less than that, it's stasis. ... Stasis in the context of PE, which is what we're presumably discussing, is within species. ... I object to living fossils being called examples of stasis. ... No, it's one explanation for stasis, and your suggested form of stabilizing selection is only one among many explanations that incorporate stabilizing selection, not to mention those that don't. ...
    (talk.origins)