[Taxacom] Fwd: Yoder, dispersal, and Madagascar's biota

Tue Mar 25 14:32:46 CDT 2014

Ken,

Who do you cite in support of their not being sister groups?

John Grehan

On Wed, Mar 26, 2014 at 8:27 AM, Ken Kinman <kinman at hotmail.com> wrote:

> Hi John,
>         Yes, we can definitely agree that Dougherty was wrong about a
> transoceanic dispersal of primitive frogs.  But that is because Ascaphidae
> and Leiopelmatidae are not sister groups (their shared characteristics are
> symplesiomorphies, not synapomorphies).  And hopefully you no longer have a
> "track" connecting them across the Pacific, because that would also be very
> misleading.  Unfortunately, the "Tree of Life" still seems to show them as
> sister groups, but it is terribly out of date.
>
>                            -----------------Ken Kinman
>
>
> ---------------------------------------------------------------------------------------------------------------------------------------------------------------------
>
> > Date: Wed, 26 Mar 2014 06:38:37 +1300
> > From: calabar.john at gmail.com
> > To: phovenkamp at casema.nl
> > CC: taxacom at mailman.nhm.ku.edu
> > Subject: Re: [Taxacom] Fwd: Yoder, dispersal, and Madagascar's biota
>
> >
> > Peter,
> >
> > Not sure if I ever remember exactly what I said yesterday. I think the
> key
> > point is that chance dispersal does not anticipate vicariant
> relationships
> > or spatial correlations with tectonics which would not occur if chance
> > dispersal was the driving force in evolutionary differentiation. Yes one
> > might appeal to chance to explain the iguana or frog, but it is not
> > necessary.
> >
> > Yes we might agree that its hard to believe, but some do believe. Years
> ago
> > the herpetologist Dr. Charles Dougherty gave a presentation at Victoria
> > University of Wellington where he said a molecular clock estimated
> > divergence between the NZ frog and its N American relative at 20 Ma so
> the
> > NZ frog rafted from North America (somehow not the other way). So he was
> > willing to believe.
> >
> > John Grehan
> >
> >
> > On Wed, Mar 26, 2014 at 4:58 AM, Phovenkamp at casema Nl
> > <phovenkamp at casema.nl>wrote:
> >
> > > John,
> > >
> > > I remember repeated assertions (by you, Michael Heads, or even the
> three
> > > of you with Robin Craw) that long-distance dispersal is a process that
> does
> > > not generate patterns (I even remember having made that assertion
> myself a
> > > few times, so I must be excused in taking it seriously).
> > >
> > > But the consequence of that assertion is that lack of a general pattern
> > > cannot be cited as a problem for a dispersalist explanation. It's a
> > > relatively simple argument: common causes: repeated patterns;
> > > long-distance dispersal: haphazard patterns.
> > >
> > > The erratic route along which the frog rafted across the Pacific,
> > > bypassing Fiji and Samoa, is thus exactly what one would expect when
> LDD is
> > > playing a role.
> > >
> > > Personally, I find it as hard as you do to believe in frogs sitting on
> > > rafts and somehow surviving a journey across the Pacific without either
> > > dying form starvation, extreme sunburn or simply no longer being able
> to
> > > withstand the urge to jump, but that it has missed a small speck at the
> > > horizon, I can understand that.
> > >
> > >
> > > Peter Hovenkamp
> > >
> > > Op 25 maart 2014 om 11:42 schreef John Grehan <calabar.john at gmail.com
> >:
> > >
> > >
> > >
> > > I would add to Mike's point "you have to explain that in a way that
> fits
> > > with the rest of the pattern." as time and time again dispersal
> > > explanations that seem to provide a tidy explanation for one instance
> > > generate a string of contradictory anomalies that are somehow never
> > > addressed (and perhaps not even recognized since there is no need in
> > > dispersal biogeography to examine, let alone look for patterns). The
> > > primitive NZ frog is supposed to have rafted cross the Pacific from the
> > > northern Rockies but did not make it to Fiji or Samoa or anywhere else
> > > while iguanas are supposed to have made the trip to Fiji and Samoa but
> not
> > > to NZ or anywhere else etc, etc.
> > >
> > >
> > > John Grehan
> > >
> > >
> > > On Tue, Mar 25, 2014 at 5:01 PM, Michael Heads <m.j.heads at gmail.com>
> > > wrote:
> > >
> > > > Hi Ken,
> > > >
> > > > You said about Yoder's study: 'I thought it was a very thoughtful and
> > > > balanced review, and how Michael dismisses the included studies as
> ONLY
> > > > showing the importance of calibration method has me scratching my
> head in
> > > > disbelief'.
> > > >
> > > > All the studies (except one) used one calibration method (fossils)
> and
> > > > inferred the same process (dispersal). The only other paper used a
> very
> > > > different calibration method (tectonics) and inferred a totally
> different
> > > > result (vicariance). The only obvious conclusion is that calibration
> is
> > > > crucial and that there are unresolved issues.
> > > >
> > > > Looking at it in more detail, neither the reviewed papers nor the
> review
> > > > itself addressed the problem of the 'priors' used in dating
> analyses. In
> > > > other words, how much older than the oldest fossil can its clade be?
> > > >
> > > > The Yoder work on Madagascar is discussed in more length elsewhere
> in my
> > > > 2012 book. I also discussed the Ali and Huber work you mentioned:
> 'The
> > > Ali
> > > > and Huber paper solved the "problem" of ocean currents...'. I think
> you
> > > > should read my book! A&H explained how lemurs might have been
> stranded in
> > > > Madagascar by rafting, but this is only part of the Madagascar
> puzzle.
> > > > Strepsirrhines are in Africa and Madagascar (lemurs), but not
> > > > America, while haplorhines are in Africa and America, but not
> Madagascar.
> > > > This is a very symmetrical structure. If strepsirrhines could raft to
> > > > Madagascar, why did not haplorhines? And why could haplorrhines
> manage to
> > > > raft to America when they couldn't even get to Madagascar? A&H didn't
> > > > address these aspects. You can't just answer one part of the problem
> -
> > > > anyone can think up an ad hoc reason for one particular step. In
> > > addition,
> > > > haplorhines are more diverse in western Africa, strepsirrhines in
> east
> > > > Africa - you have to explain that in a way that fits with the rest
> of the
> > > > pattern.
> > > >
> > > > Michael
> > > >
> > > >
> > > > On Tue, Mar 25, 2014 at 2:45 AM, Ken Kinman <kinman at hotmail.com>
> wrote:
> > > >
> > > > > Michael and John,
> > > > >
> > > > > Well, the funny thing is that I was inclined to give you the
> > > > benefit
> > > > > of the doubt on cichlids (as was Yoder and Nowak), but I am now
> > > actually
> > > > > less inclined to do so. I would like to emphasize the last two
> > > > sentences
> > > > > of Yoder and Nowak's abstract: "For those studies that include
> > > > > divergence time analysis, we find an overwhelming indication of
> > > Cenozoic
> > > > > origins for most Malagasy clades. We conclude that most of the
> > > > present-day
> > > > > biota of Madagascar is comprised of the descendents of Cenozoic
> > > > dispersers,
> > > > > predominantly with African origins." I think that their use of the
> word
> > > > > "overwhelming" is important to note, and I found no reason to think
> > > that
> > > > > they were exaggerating in doing so. As for the cichlids in
> particular,
> > > > > in the text they admit that among the vertebrates, "the cichlid
> ﬁshes
> > > of
> > > > Madagascar
> > > > > represent the most challenging puzzle for differentiating
> vicariance
> > > > from dispersal."
> > > > > And then they are careful to give the arguments either way. I
> thought
> > > > it
> > > > > was a very thoughtful and balanced review, and how Michael
> dismisses
> > > the
> > > > > included studies as ONLY showing the importance of calibration
> method
> > > has
> > > > > me scratching my head in disbelief. I think that it is a narrow and
> > > > unfair
> > > > > assessment of the Yoder and Nowak review and of the studies they
> were
> > > > > reviewing.
> > > > >
> > > > > It's too bad Michael (in 2012) obviously didn't have the more
> > > > > recently published and thorough study on the subject of cichlid
> > > > > biogeography, which concluded that it was dispersal, not
> vicariance,
> > > > which
> > > > > produced the present distribution of those fishes: Title:
> > > > > Molecular and fossil evidence place the origin of cichlid fishes
> long
> > > > > after Gondwanan rifting.
> > > > > by Matt Friedman<
> > > >
> > >
> http://rspb.royalsocietypublishing.org/search?author1=Matt+Friedman&sortspec=date&submit=Submit
> > > > >
> > > > > ,
> > > > > Benjamin P. Keck<
> > > >
> > >
> http://rspb.royalsocietypublishing.org/search?author1=Benjamin+P.+Keck&sortspec=date&submit=Submit
> > > >,
> > > > et
> > > > > al., 2013. They state:
> > > > > "It is important to note that our relaxed-molecular-clock analysis
> > > > > shares no palaeontological data in common with either our analysis
> of
> > > the
> > > > > distribution of cichlid-bearing fossil horizons or our database of
> > > > > outgroup-based age constraints. We interpret the convergence of
> these
> > > > three
> > > > > semi-independent approaches, which all deliver age estimates for
> > > cichlids
> > > > > that are within error of one another, as a consequence of genuine
> > > > > evolutionary signal that strongly contradicts the time scales for
> > > > cichlids
> > > > > demanded by hypotheses of Gondwanan vicariance."
> > > > >
> > > > > And even if one doesn't agree with Friedman et al.'s conclusions,
> > > > > the cichlids are just one of many taxa reviewed by Yoder and
> Nowak, not
> > > > > only among vertebrates, but plants and invertebrates as well. Many
> > > > appear
> > > > > to have dispersed late enough that it stretches credibility to
> suggest
> > > > that
> > > > > fossil calibration is a problem with so many of them dispersing (as
> > > > opposed
> > > > > to a very early vicariance). Especially the rodent and carnivore
> > > > dispersal
> > > > > between 20 and 25 million years ago (see Ali and Huber, 2010;
> *Nature*
> > > > > *463*, 653-656; Mammalian biodiversity on Madagascar controlled by
> > > ocean
> > > > > currents). The Ali and Huber paper solved the "problem" of ocean
> > > > currents
> > > > > presumably going the wrong way for dispersal to occur, showing
> that the
> > > > > currents went the other way in the early-to-mid Tertiary.
> > > > >
> > > > >
> > > > > -------------------Ken Kinman
> > > > >
> > > > >
> > > > > ------------------------------
> > > > > Date: Sat, 22 Mar 2014 10:46:58 +1300
> > > > > Subject: Re: [Taxacom] Madagascar's biota overwhelmingly from
> Cenozoic
> > > > > dispersers
> > > > > From: m.j.heads at gmail.com
> > > > > To: kinman at hotmail.com; taxacom at mailman.nhm.ku.edu
> > > > >
> > > > > Hi Ken,
> > > > >
> > > > > Here is what I wrote (2012) about Yoder and Nowak's paper:
> > > > >
> > > > > Yoder and Nowak (2006) gave a thorough review of the molecular
> clock
> > > > > literature on Malagasy taxa. In every study of plants the
> > > > fossil-calibrated
> > > > > clocks dated the Madagascar clades as younger than 80 Ma and so
> they
> > > were
> > > > > all attributed to post-Gondwana dispersal, none to vicariance.
> With a
> > > > > single exception, studies of animal taxa showed the same result.
> All
> > > > > molecular dating studies of Malagasy invertebrates, reptiles and
> > > mammals
> > > > > have concluded in favor of dispersal, as the inferred
> > > (fossil-calibrated)
> > > > > divergence times were post-Mesozoic. The only sequenced group in
> Yoder
> > > > and
> > > > > Nowak’s review (2006) whose presence on Madagascar has been
> attributed
> > > to
> > > > > vicariance is the fish family Cichlidae. Molecular dating studies
> of
> > > this
> > > > > group avoided the use of fossil calibrations completely (Sparks,
> 2004,
> > > > > Sparks and Smith, 2004; see Chapter 2). Instead, the vicariant
> > > > distribution
> > > > > of the two main molecular clades: Madagascar-Africa-South America,
> and
> > > > > Madagascar-India-Sri Lanka, was correlated with tectonics – the
> opening
> > > > of
> > > > > the Mozambique Channel – and this was used as a calibration. (The
> same
> > > > > method is used here for primates). So although Yoder and Nowak
> (2006:
> > > > 416)
> > > > > concluded that the importance of dispersal ‘cannot be denied’,
> really
> > > the
> > > > > only thing the cited studies show is the importance of the
> calibration
> > > > > method.
> > > > >
> > > > > Michael Heads
> > > > >
> > > > >
> > > > > On Sat, Mar 22, 2014 at 7:49 AM, Ken Kinman <kinman at hotmail.com>
> > > wrote:
> > > > >
> > > > > Has Vicariance or Dispersal Been the Predominant Biogeographic
> Force in
> > > > > Madagascar? Only Time Will TellAnnual Review of Ecology,
> Evolution, and
> > > > > SystematicsVol. 37: 405-431 DOI:
> > > > 10.1146/annurev.ecolsys.37.091305.110239by
> > > > > Anne D. Yoder and Michael D. Nowak
> > > > > Abstract. Madagascar is one of the world's hottest biodiversity hot
> > > > > spots due to its diverse, endemic, and highly threatened biota.
> This
> > > > biota
> > > > > shows a distinct signature of evolution in isolation, both in the
> high
> > > > > levels of diversity within lineages and in the imbalance of
> lineages
> > > that
> > > > > are represented. For example, chameleon diversity is the highest
> of any
> > > > > place on Earth, yet there are no salamanders. These biotic enigmas
> have
> > > > > inspired centuries of speculation relating to the mechanisms by
> which
> > > > > Madagascar's biota came to reside there. The two most probable
> causal
> > > > > factors are Gondwanan vicariance and/or Cenozoic dispersal. By
> > > reviewing
> > > > a
> > > > > comprehensive sample of phylogenetic studies of Malagasy biota, we
> find
> > > > > that the predominant pattern is one of sister group relationships
> to
> > > > > African taxa. For those studies that include divergence time
> analysis,
> > > we
> > > > > find an overwhelming indication of Cenozoic origins for most
> Malagasy
> > > > > clades. We conclude that most of the present-day biota of
> Madagascar is
> > > > > comprised of the descendents of Cenozoic dispersers, predominantly
> with
> > > > > African origins.
> > > > >
> > > > >
> > > > >
> > > > > ______________________________________________
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > >
> > > >
> > > > --
> > > > 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
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> > > > The Taxacom Archive back to 1992 may be searched at:
> > > > http://taxacom.markmail.org
> > > >
> > > > Celebrating 27 years of Taxacom in 2014.
> > > >
> > > _______________________________________________
> > > Taxacom Mailing List
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> > > The Taxacom Archive back to 1992 may be searched at:
> > > http://taxacom.markmail.org
> > >
> > > Celebrating 27 years of Taxacom in 2014.
> > >
> > >
> > _______________________________________________
> > Taxacom Mailing List
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> > 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.
>