[Taxacom] Deja vu (too much vicariance)

[John Grehan]

Hi Ken,

Regarding your 2014 statement that “they don't seem to "realize how
devastating the K-T extinction event was to the biota of Madagascar, and
how that cleared the way for the vertebrate dispersers during the
Cenozoic."

This is not a fact, but a conjecture. And it is one that is not supported
by the biogeographic evidence. While the K-T event may have been
devastating, it did not eliminate everything. A great deal of 'modern' life
apparently did survive.

 "In spite of the growing amounts of evidence for Cenozoic dispersal (for
invertebrates and plants, as well as vertebrates)...”

There is none.

“you [John] always retreat to your fallback position complaining about
"minimal estimates", but your imagined "maximal estimates" would often have
to be so old that they seem even more problematic.”

They are not maximal estimates, but estimates of an actual date. So it
seems here that you accept that the minimum age criterion of fossils is
correct, except you cannot accept that the older ages proposed from
tectonic correlation. But your personal rejection of those older ages being
“more problematic” (how?, specify cases) is not of itself a
counter-evidence.

"Perhaps there was more Cenozoic vicariance in Australasia"

More than what? Explain that.

“but if you keep on harping about dispersal to Madagascar, it makes people
wonder if you are also exaggerating the role of vicariance elsewhere.”

Until dispersalists come up with some actual evidence, of course I might
keep 'harping' on it. And especially if it continues the misrepresentation
(notice I did not say fraudulent again, just to soothe unsettled nerves) of
fossil calibrated data as anything but a minimum estimate, then of course I
will keep drawing attention to it. One need not ignore bad science (or at
least what one considers to be bad science) just because a lot of people
practice it.

Cheers, John

On Mon, Nov 29, 2021 at 8:39 AM Kenneth Kinman via Taxacom <
taxacom at mailman.nhm.ku.edu> wrote:

> Hi Jason,
>          I certainly agree that "Even if people were marginally
> sympathetic to panbiogeography, the over the top language would harden
> their stance."  But it would be technically more accurate to say "too much
> vicariance team".  This is especially true when it comes to Madagascar.  As
> I said in a post in 2014, they don't seem to "realize how devastating the
> K-T extinction event was to the biota of Madagascar, and how that cleared
> the way for the vertebrate dispersers during the Cenozoic."
>          I also said:  "In spite of the growing amounts of evidence for
> Cenozoic dispersal (for invertebrates and plants, as well as vertebrates),
> you [John] always retreat to your fallback position complaining about
> "minimal estimates", but your imagined "maximal estimates" would often have
> to be so old that they seem even more problematic. Perhaps there was more
> Cenozoic vicariance in Australasia, but if you keep on harping about
> dispersal to Madagascar, it makes people wonder if you are also
> exaggerating the role of vicariance elsewhere. "    Source:
> http://mailman.nhm.ku.edu/pipermail/taxacom/2014-March/126916.html
>
>                    -----------Ken Kinman
>
> ________________________________
> From: Taxacom <taxacom-bounces at mailman.nhm.ku.edu> on behalf of John
> Grehan via Taxacom <taxacom at mailman.nhm.ku.edu>
> Sent: Monday, November 29, 2021 12:33 AM
> To: Michael Heads <m.j.heads at gmail.com>
> Cc: Taxacom <taxacom at mailman.nhm.ku.edu>; Jason Mate <
> polyphagans at gmail.com>
> Subject: Re: [Taxacom] Taxacom Digest, Vol 187, Issue 18
>
> Now, now Jason. It's one thing to object to the way I describe a particular
> approach, but another to create an "all vicariance team".  See Heads'
> response on that. And it is incorrect to say that I am complaining "that
> they are using timing to discern between tectonics and active dispersal".
> Not at all. What I am 'complaining' about is the continued use of
> the fiction that fossil calibrated estimates somehow generate actual ages
> when they don't. And they carry this on as if this has never been pointed
> out. That is why it is a fiction, and why their approach is garbage - in my
> opinion. A fossil can empirically generate only an actual date for the
> oldest known record. One may have personal views about limiting how much
> older a taxon may be, but that estimate cannot come from the fossil. A
> minimum is a minimum, is a minimum.
>
> I would also note that many have dismissed panbiogeography as 'garbage' one
> way or another, and I have no problem with that as everyone is entitled to
> their personal view, but how they reach that opinion is up for challenge,
> at least in science, in theory anyway. Some try to get around that little
> impediment by trying to have panbiogeography suppressed so they can
> presumably avoid having to defend their views from critique.
>
> Cheers,
>
> John Grehan
>
> On Mon, Nov 29, 2021 at 1:16 AM Michael Heads via Taxacom <
> taxacom at mailman.nhm.ku.edu> wrote:
>
> > I don't know any 'all-vicariance biogeographer', let alone a team. Can
> you
> > name any? If evolution really was 'all vicariance', every species would
> > have its own range, shared with no other.
> >
> > On Mon, Nov 29, 2021 at 6:48 PM Jason Mate via Taxacom <
> > taxacom at mailman.nhm.ku.edu> wrote:
> >
> > > "Here's another predictable example of garbage biogeography. Garbage,
> > > because ...
> > > ...maintaining the fiction ...
> > > It's all a total fabrication, now verging on fraud ..."
> > >
> > > Even if people were marginally sympathetic to panbiogeography, the over
> > the
> > > top language would harden their stance. What you are complaining about,
> > > again, is that they are using
> > > timing to discern between tectonics and active dispersal. We already
> know
> > > the "all-vicariance-team" has no room for the latter so... what's new?
> > >
> > > Jason
> > >
>
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