[Taxacom] Test Questions (was: Panbiogeography)

Sun Apr 6 12:12:54 CDT 2014

Hi All,

I've only been partially paying attention to this thread, but Jason's recent
post (which captured my own general perspective nicely) has encouraged me to
ask some questions:

1) Does everyone agree that there is ample evidence that some populations of
organisms have been fractioned via rare vicariant events, leading to
reproductive isolation and subsequent divergence and, ultimately,
speciation?

2) Does everyone agree that there is ample evidence that some populations of
organisms have been fractioned via rare dispersal events, leading to
reproductive isolation and subsequent divergence and, ultimately,
speciation?

If anyone's answer to either question is "No", I would like to hear an
explicit statement of such, accompanied by explanations that counter the
aforementioned ample evidence (which has been, and could easily be, provided
by members of this list) in specific, individual situations.

If we all agree that the answer to both questions is "Yes", then can someone
explain what this seemingly never-ending debate is really about?  Is it
simply about the relative frequency of each mechanism, across broader
biodiversity, that has historically resulted in reproductively isolated
populations and subsequent speciation?  If so, then the next question is:

3) Are we arguing about 95/5 one way or the other, or more like 60/40 one
way or the other?

Some additional questions:

4) Is anyone willing to step up to the plate to discuss cases where
speciation seems to have occurred in the absence of geographic isolation
(i.e., no dispersal or vicariant events required)?

5) Does someone want to take a stab at defining the scope of "broader
biodiversity" alluded to in the preamble to question #3 above? (There seems
to be a lot of focus on terrestrial vertebrates and plants -- does the
debate also include marine organisms?  What about insects?  Microbes? Can
vicariance or dispersal explain patterns of bacteria diversity?)

6) Imagine a hypothetical(?) situation where infrequent events like global
glaciation cycles cause substantial sea-level changes, which have dramatic
impact to ocean currents and thereby shifts in patterns of dispersal
potential/frequency among marine organisms with planktonic larvae -- such
that geographically disjoint populations that have high potential gene flow
during long periods of time, undergo long periods of time with very low
potential gene flow.  In such cases, where speciation results during the
low-gene-flow periods, do we score a point for vicariance, or for dispersal?

Aloha,
Rich

Richard L. Pyle, PhD
Database Coordinator for Natural Sciences
Associate Zoologist in Ichthyology
Vicariant Dispersalist
Dive Safety Officer
Department of Natural Sciences, Bishop Museum
1525 Bernice St., Honolulu, HI 96817
Ph: (808)848-4115, Fax: (808)847-8252
email: deepreef at bishopmuseum.org
http://hbs.bishopmuseum.org/staff/pylerichard.html

> -----Original Message-----
> From: taxacom-bounces at mailman.nhm.ku.edu [mailto:taxacom-
> bounces at mailman.nhm.ku.edu] On Behalf Of Michael Heads
> Sent: Sunday, April 06, 2014 12:17 AM
> To: JF Mate
> Cc: Taxacom
> Subject: Re: [Taxacom] Panbiogeography
> 
> Hi Jason,
> 
> Getting back to the facts, a taxacomer just sent me a classic that I
hadn't
> spotted: a chameleon on Socotra that has a diverse sister group widespread
> through the Sahel (Mali to Somalia), around the Mediterranean, Saudi
Arabia
> and east to India (not on Socotra). It's in Macey et al., 2008 Mol
Phylogen Evol
> 49: 1015.
> 
> This is the sort of thing you see in many groups in the Caribbean and the
SW
> Pacific. It's very simple to explain the pattern by an early break in a
> widespread ancestor, somewhere around Socotra. If you want to explain it
> by the usual dispersal from the mainland, you have to bring in other, ad
hoc
> hypotheses. But the main point is just how starkly and beautifully it
highlights
> the significance of Socotra, whatever the actual mechanism.
> 
> Michael
> 
> 
> On Sun, Apr 6, 2014 at 7:08 PM, JF Mate <aphodiinaemate at gmail.com>
> wrote:
> 
> > Hi Ken. Sorry for replying so late but i am currently travelling around.
> > Your optimism is refreshing but ultimately a waste of effort. There is
> > no evidence that you can offer them that will satisfy them because you
> > don't know (or them I suspect) what they are arguing against. Whereas
> > you, I or most others can accept vicariance and dispersal as
> > mechanisms (and have said so repeatedly) we are labelled dispersalists.
Go
> figure.
> > When you show them clear, factual evidence of organisms being sent
> > across the ocean, these events are either "too frequent" or so
> > infrequent that the probabilities cannot be calculated and therefore
> > no different to astrology (so much for only being interested in data).
> > What you will never be shown are the definitions under which they
> > operate. Funny since they are interested in patterns and this requires
> > some sort of operational definitions. But when a man's livelihood
> > depends on not understanding something, then they won't, no matter
> what you say.
> > "It doesn't matter how beautiful your theory is, it doesn't matter how
> > smart you are. If it doesn't agred with experiment, it's wrong." Stuff
> > can cross oceans, let them fight facts if they want. I have critters to
catch.
> >
> > Best
> >
> > Jason
> > _______________________________________________
> > Taxacom Mailing List
> > Taxacom at mailman.nhm.ku.edu
> > http://mailman.nhm.ku.edu/mailman/listinfo/taxacom
> > The Taxacom Archive back to 1992 may be searched at:
> > http://taxacom.markmail.org
> >
> > Celebrating 27 years of Taxacom in 2014.
> >
> 
> 
> 
> --
> Dunedin, New Zealand.
> 
> My recent books:
> 
> *Molecular panbiogeography of the tropics.* 2012. University of California
> Press, Berkeley. www.ucpress.edu/book.php?isbn=9780520271968
> 
> *Biogeography of Australasia:  A molecular analysis*. 2014. Cambridge
> University Press, Cambridge. www.cambridge.org/9781107041028
> _______________________________________________
> Taxacom Mailing List
> Taxacom at mailman.nhm.ku.edu
> http://mailman.nhm.ku.edu/mailman/listinfo/taxacom
> The Taxacom Archive back to 1992 may be searched at:
> http://taxacom.markmail.org
> 
> Celebrating 27 years of Taxacom in 2014.