[Taxacom] Long-distance oceanic dispersal (rafting) of Nothofagus species

John Grehan calabar.john at gmail.com
Sun Jun 3 19:55:29 CDT 2018


Hawaii is a classic example of what?

John Grehan

On Sun, Jun 3, 2018 at 8:53 PM, Stephen Thorpe <stephen_thorpe at yahoo.co.nz>
wrote:

> Evidence for long distance dispersal over vicariance must take into
> account entire biotas, not just selected taxa. Hawaii is the classic
> example.
>
> Stephen
>
> --------------------------------------------
> On Mon, 4/6/18, John Grehan <calabar.john at gmail.com> wrote:
>
>  Subject: Re: [Taxacom] Long-distance oceanic dispersal (rafting) of
> Nothofagus species
>  To: "Barry OConnor" <bmoc at umich.edu>
>  Cc: "taxacom at mailman.nhm.ku.edu" <taxacom at mailman.nhm.ku.edu>
>  Received: Monday, 4 June, 2018, 12:49 PM
>
>  Barry,
>
>  An answer to your question requires a bit of a
>  clarification about
>  dispersal and its
>  relationship to biogeographic origin of allopatric taxa
>  (which is what most biogeographic controversies
>  are about), although
>  probably best to read
>  discussion about that in a more structured account
>  such as you will find in Heads' books .
>  Dispersal as an ordinary ecological
>  process
>  is what we observe in real time. It results in survival of
>  the
>  species and may result in range
>  expansion under particular circumstances.
>  Differentiation of allopatric taxa requires
>  isolation. If dispersal is so
>  pervasive as
>  to preclude isolation then there cannot be allopatric
>  differentiation. This is the tangle that
>  emerges when dispersal is used as
>  the
>  mechanism to explain biogeographic patterns of allopatry. A
>  resolution
>  of this paradox is to view
>  dispersal as operative in establishing ancestral
>  range rather than creating isolated entities.
>  So seeing  *Anolis* lizard on
>  a raft of
>  hurricane debris just off a Caribbean island is effectively
>  no
>  different from seeing any other organism
>  moving or moved about. It has
>  immediate
>  ecological significance (in terms of metapopulation survival
>  for
>  example - again characterized in more
>  detail by Heads) but its
>  biogeographic role
>  cannot be assumed.
>
>  John
>  Grehan
>
>  On Sun, Jun 3, 2018
>  at 7:28 PM, Barry OConnor <bmoc at umich.edu>
>  wrote:
>
>  > I'm curious
>  - what is *evidence* of chance dispersal other than, say,
>  > seeing an *Anolis* lizard on a raft of
>  hurricane debris just off a
>  > Caribbean
>  island? - Barry
>  >
>  > On
>  Sun, Jun 3, 2018 at 7:08 PM, Kenneth Kinman <kinman at hotmail.com>
>  wrote:
>  >
>  >>
>  John,
>  >>
>  >>
>     Well, you tossing out such red herrings will not
>  dissuade me.
>  >> Including the
>  scientific one about frogs.  The two primitive frog
>  families
>  >> originated way back in the
>  Paleozoic when the world map was much different
>  >> (Gondwanaland still largely intact).
>  No long-distance dispersal
>  >>
>  necessary.  Vicariance explains that case quite nicely.
>  Nothofagus evolved
>  >> much later
>  (after the break up Gondwana), so I don't know why you
>  tossed
>  >> out that red herring.
>  And comparing my hypothesis to UFOs or an Act of
>  >> God could be interpreted as a bit
>  insulting.  And in your second post
>  >> saying that "Chance dispersal
>  continues to hold a very visceral appeal for
>  >> evolutionary biologists", seems
>  to indicate to me that many
>  >>
>  panbiogeographers tend to overstate the importance of
>  vicariance and too
>  >> often either
>  ignore or attack evidence for chance dispersal when it is
>  >> presented.  I suspect that is what
>  will happen if any evidence is found to
>  >> support my hypothesis.  One thing is
>  certain---we won't find such evidence
>  >> if we don't look for it.
>  >>
>  >>
>        -------------Ken
>  >>
>  >> P.S.  Your latest comment about
>  "fairy tales" was a bit rude.  I don't
>  >> see why the explanation I put forward
>  and question I asked of Bart should
>  >>
>  be characterized as fairy tales.
>  >>
>  >>
>  >>
>  ________________________________
>  >>
>  From: John Grehan <calabar.john at gmail.com>
>  >> Sent: Sunday, June 3, 2018 9:46 AM
>  >> To: Kenneth Kinman
>  >> Cc: Stephen Thorpe; taxacom at mailman.nhm.ku.edu
>  >> Subject: Re: [Taxacom] Long-distance
>  oceanic dispersal (rafting) of
>  >>
>  Nothofagus species
>  >>
>  >> Ken,
>  >>
>  >> Its not a testable notion in any real
>  sense any more than attributing the
>  >>
>  connection to UFO's. Further, it is not an 'odd'
>  distribution, but one that
>  >> is very
>  even (meaning standard). One can invoke any number of
>  imaginary
>  >> events to toss plants and
>  animals from one side of the Tasman to the other,
>  >> or even just place them there by an
>  Act of God, but there is no empirical
>  >> imperative to do so for this any more
>  than imagining a tsunami to toss
>  >>
>  frogs from Vancouver to New Zealand.
>  >>
>  >> John
>  Grehan
>  >>
>  >> On
>  Sun, Jun 3, 2018 at 8:38 AM, Kenneth Kinman <kinman at hotmail.com
>  >> <mailto:kinman at hotmail.com>>
>  wrote:
>  >> Hi Stephen,
>  >>
>  >>       But
>  it could be somewhat scientifically testable if some
>  organisms
>  >> (mostly likely insects)
>  have the same odd distribution in New Zealand and
>  >> Tasmania (or adjacent Australia).  So
>  I am hoping that some entomologist
>  >>
>  might know of insects that fit the bill.  And if there were
>  more than one
>  >> such organism, the
>  more likely this dispersal scenario would become.
>  >>
>  >>
>  And note that I cited two different Nothofagus species
>  groups with
>  >> the same odd
>  distribution (one in subgenus Lophozonia and the other in
>  >> subgenus Fuscospora).  And those two
>  dispersals could have happened at
>  >>
>  different times.  So that already increases the probability
>  of dispersal.
>  >> Anyway, at least Fred
>  understood what I was suggesting:
>  >>
>  http://mailman.nhm.ku.edu/pipermail/taxacom/2006-December/108388.html
>  >>
>  >>
>  >> -----------------Ken
>  >>
>  >>
>  ________________________________
>  >>
>  From: Stephen Thorpe <stephen_thorpe at yahoo.co.nz<mailto:
>  >> stephen_thorpe at yahoo.co.nz>>
>  >> Sent: Saturday, June 2, 2018 8:59
>  PM
>  >> To: Kenneth Kinman
>  >> Cc: taxacom at mailman.nhm.ku.edu<mailto:taxacom at mailman.nhm.ku.edu>
>  >> Subject: Re: [Taxacom] Long-distance
>  oceanic dispersal (rafting) of
>  >>
>  Nothofagus species
>  >>
>  >> "Could certain insects, mosses,
>  or other organisms have hitched a ride on
>  >> such a Nothofagus raft?"
>  >>
>  >> Impossible to
>  rule out just about anything that doesn't constantly
>  >> require running freshwater. If it
>  happened during summer, there could be a
>  >> desiccating effect, but at other times
>  the amount of freshwater dampness
>  >>
>  could remain at acceptable levels.
>  >>
>  >> The problem
>  though, as I see it, is that these dispersion events are
>  >> entirely random and unpredictable, so
>  it is hard to base much in the way of
>  >> science on it.
>  >>
>  >> Stephen
>  >>
>  >>
>  --------------------------------------------
>  >> On Sun, 3/6/18, Kenneth Kinman <kinman at hotmail.com<mailto:kin
>  >> man at hotmail.com>>
>  wrote:
>  >>
>  >>
>  Subject: [Taxacom] Long-distance oceanic dispersal (rafting)
>  of
>  >> Nothofagus      species
>  >>  To: "Kenneth Kinman"
>  <kinman at hotmail.com<mailto:kinman at hotmail.com>>
>  >>  Cc: "taxacom at mailman.nhm.ku.edu<mailto:taxacom at mailman.nhm.ku.edu>"
>  <
>  >> taxacom at mailman.nhm.ku.edu<mailto:taxacom at mailman.nhm.ku.edu>>
>  >>
>  >>  Received:
>  Sunday, 3 June, 2018, 1:51 PM
>  >>
>  >>  Hi all,
>  >>
>  >>  The recent thread got me thinking
>  about a debate that some
>  >>  of us
>  were having on taxacom almost 12 years ago.  Namely
>  >>  whether long-distance oceanic
>  dispersal (by rafting) was a
>  >>
>  significant factor in the geographic distribution of some
>  >>  species of Nothofagus (sensu
>  lato).
>  >>
>  >>
>  My hypothesis was that large rafts of dislodged
>  Nothofagus
>  >>  trees (due to tsunami
>  or other massive flooding event) could
>  >>  have held some of their fruit above
>  the ocean surface and
>  >>  rafted from
>  Tasmania to New Zealand, where one or more  new
>  >>  species could evolve (due to founder
>  effect).  This would
>  >>  be a
>  relatively short rafting event compared to the much
>  >>  longer driftwood oceanic rafting
>  that happened from South
>  >>  America
>  to Tasmania: Barber, 1959, in the journal Nature;
>  >>  "Transport of Driftwood from
>  South America to
>  >>  Tasmania".
>  Is there other evidence that such dispersal
>  >>  of Nothofagus could have happened?
>  Could certain insects,
>  >>  mosses, or
>  other organisms have hitched a ride on such a
>  >>  Nothofagus raft?
>  >>
>  >>
>           --------------Ken Kinman
>  >>  http://mailman.nhm.ku.edu/pipermail/taxacom/2006-December/108385.html
>  >>
>  _______________________________________________
>  >>  Taxacom Mailing List
>  >>  Send
>  >>
>  Taxacom mailing list submissions to: Taxacom at mailman.nhm.ku.edu<mailto:
>  >> Taxacom at mailman.nhm.ku.edu>
>  >>
>  >>  http://mailman.nhm.ku.edu/cgi-bin/mailman/listinfo/taxacom
>  >>  The Taxacom Archive back to 1992 may
>  be
>  >>  searched at: http://taxacom.markmail.org
>  >>  To subscribe or unsubscribe via the
>  Web, visit:
>  >>  http://mailman.nhm.ku.edu/cgi-bin/mailman/listinfo/taxacom
>  >>  You can reach the person managing
>  the list at:
>  >>  taxacom-owner at mailman.nhm.ku.edu<mailto:taxacom-owner@
> mailman.nhm.ku.edu
>  >> >
>  >>
>  >>  Nurturing Nuance while
>  >>  Assaulting Ambiguity for 31 Some
>  Years, 1987-2018.
>  >>
>  >>
>  _______________________________________________
>  >> Taxacom Mailing List
>  >> Send Taxacom mailing list submissions
>  to: Taxacom at mailman.nhm.ku.edu<mai
>  >> lto:Taxacom at mailman.nhm.ku.edu>
>  >>
>  >> http://mailman.nhm.ku.edu/cgi-bin/mailman/listinfo/taxacom
>  >> The Taxacom Archive back to 1992 may
>  be searched at:
>  >> http://taxacom.markmail.org
>  >> To subscribe or unsubscribe via the
>  Web, visit:
>  >> http://mailman.nhm.ku.edu/cgi-bin/mailman/listinfo/taxacom
>  >> You can reach the person managing the
>  list at:
>  >> taxacom-owner at mailman.nhm.ku.edu<mailto:taxacom-owner@
> mailman.nhm.ku.edu>
>  >>
>  >> Nurturing
>  Nuance while Assaulting Ambiguity for 31 Some Years,
>  1987-2018.
>  >>
>  >>
>  _______________________________________________
>  >> Taxacom Mailing List
>  >> Send Taxacom mailing list submissions
>  to: Taxacom at mailman.nhm.ku.edu
>  >>
>  >> http://mailman.nhm.ku.edu/cgi-bin/mailman/listinfo/taxacom
>  >> The Taxacom Archive back to 1992 may
>  be searched at:
>  >> http://taxacom.markmail.org
>  >> To subscribe or unsubscribe via the
>  Web, visit:
>  >> http://mailman.nhm.ku.edu/cgi-bin/mailman/listinfo/taxacom
>  >> You can reach the person managing the
>  list at:
>  >> taxacom-owner at mailman.nhm.ku.edu
>  >>
>  >> Nurturing
>  Nuance while Assaulting Ambiguity for 31 Some Years,
>  1987-2018.
>  >>
>  >
>  >
>  >
>  >
>  --
>  > -So many mites, so little time!
>  > Barry M. OConnor
>  >
>  Professor  & Curator
>  > Department of
>  Ecology & Evolutionary Biology
>  >
>  Research Museums Center
>  > University of
>  Michigan                  phone: 734-763-4354
>  > 3600 Varsity Drive
>  >
>  <https://maps.google.com/?q=3600+Varsity+Drive&entry=gmail&source=g>
>  >                    fax:
>  734-763-4080
>  > Ann Arbor, MI 48108-2228
>          e-mail: bmoc at umich.edu
>  >
>  _______________________________________________
>  Taxacom Mailing List
>  Send
>  Taxacom mailing list submissions to: Taxacom at mailman.nhm.ku.edu
>
>  http://mailman.nhm.ku.edu/cgi-bin/mailman/listinfo/taxacom
>  The Taxacom Archive back to 1992 may be
>  searched at: http://taxacom.markmail.org
>  To subscribe or unsubscribe via the Web, visit:
>  http://mailman.nhm.ku.edu/cgi-bin/mailman/listinfo/taxacom
>  You can reach the person managing the list at:
>  taxacom-owner at mailman.nhm.ku.edu
>
>  Nurturing Nuance while
>  Assaulting Ambiguity for 31 Some Years, 1987-2018.
>
>


More information about the Taxacom mailing list