[Taxacom] Oceanic dispersal vs. vicariance
Michael Heads
m.j.heads at gmail.com
Mon Jun 11 17:43:32 CDT 2018
Ken,
There has been no long-standing debate between Alan de Queiroz and myself.
I helped him out a lot with his book, providing long replies to his many
questions about the modern history of the subject in a whole series of
emails. I knew he disagreed with my views, but I was happy to help out,
even though I was very busy in Mexico at the time. I was surprised when the
book came out. I was the subject of the chapter 'Over the edge of reason'
and portrayed as barking mad. (My guess he was looking for a job and trying
to impress the right people). I wrote one article reviewing the book.
I don't have his book with me, but somewhere in it there is a whole page
plate of a painting showing a literal floating island - not just a mass of
vegetation, but a real island, with cliffs, different types of forest etc.
The island is moving in a straight line across the sea and leaving a wake
in its trail. How does that work?!
Which cases of trans-oceanic vicariance do you agree with?
On Mon, Jun 11, 2018 at 2:25 PM, Kenneth Kinman <kinman at hotmail.com> wrote:
> Hi all,
>
> I've been reading a variety of papers on the debate (beginning
> about 2005) between Alan de Queiroz (and others) on the one hand and
> Michael Heads (and others, incl. John Grehan) on the other. I have come to
> the conclusion that both sides represent polar opposites in the debate
> between oceanic dispersal and vicariance. The truth is probably somewhere
> in between, meaning that both sides are right about some cases, but wrong
> in others. Not at all surprising.
>
> Perhaps the strongest case for a large number of oceanic dispersals
> is probably from the African mainland to Madagascar. And the case for
> numerous oceanic dispersals between the African mainland and South America
> (when they were closer together) is more controversial, but there is
> apparently evidence that some of those dispersals were along island chains
> that no longer exist. Whether such islands existed or not, the debate
> between the two sides seems to be largely centered on molecular estimates
> of divergence (about which Grehan seems to repeatedly complain ad
> nauseum). Therefore, my increasing reluctance to respond to his continued
> "baiting". If he wants evidence, there is lots of evidence in the
> literature from many authors (many who seem to be somewhat more objective
> than Alan de Queiroz).
>
> The case for oceanic dispersal from Australia (including Tasmania)
> to New Zealand is admittedly even more controversial. That controversy not
> only involves molecular estimates of divergence, but also whether or not
> New Zealand was completely submerged at some time in the mid Cenozoic.
> Therefore, I am playing devil's advocate in suggesting how one or two
> species of Nothofagus could have rafted from Tasmania to New Zealand in the
> middle of the Cenozoic. Maybe they did and maybe they didn't, but both
> possibilities should be kept in mind. Given the long-standing debate
> between Alan de Queiroz and Michael Heads, I find the Nothofagus case the
> most challenging (even though some earlier Nothofagus dispersals seem
> likely to have been due to vicariance over land in Gondwana). Nothofagus
> distribution could be due to a combination of both vicariance and some
> cases of more recent oceanic dispersal.
>
> ------------------Ken
>
>
> ________________________________
> From: John Grehan <calabar.john at gmail.com>
> Sent: Thursday, June 7, 2018 10:08 AM
> To: Kenneth Kinman
> Cc: Michael Heads; Taxacom
> Subject: Re: Oceanic dispersal (rafting) of mammals in particular
>
>
> Hi Ken,
>
>
> Thanks for your latest observations on the subjects. Some reflections
> below.
>
>
>
> “I do not object to vicariance (it explains many distribution
> patterns). I just think panbiogeographers tend to overdo vicariance, and
> you in particular have a tendency to start ranting when vicariance is
> challenged in some cases. So I probably won't be doing any more posts on
> the subject.”
>
>
>
> No problem with that. All counter responses may be viewed that way. That
> is why I have said that what is important is how a particular view is
> connected to the evidence and the nature of that evidence. And why should I
> not 'rant' when vicariance is challenged? Is that not the nature of science
> in general? I suppose one could ignore alternative views and that also is a
> choice scientists often make (at least in evolutionary biology).
>
>
>
> “I will just close by saying that there seems to be a pattern of
> Africa to South America transoceanic dispersal which also includes
> caviomorph rodents, the hoatzin, and lots of different small reptiles
> (amphisbaenians, geckos, skinks, lizards, and blind snakes). So the New
> World monkeys would not be an isolated case.”
>
>
>
> So you keep saying. And I keep asking for your to explicitly state the
> nature of the evidence, which you keep avoiding. I have no problem with
> your presenting your view as we are all entitled to that, but to avoid
> making a reasoned argument as to the nature of the evidence and how that
> indicates your model and falsifies other evidence of vicariance is
> problematic to say the least. It is as if you are trying to protect your
> 'evidence' from external scrutiny (which again is the nature of being
> scientific). If your view is so strongly supported by evidence I would have
> thought you would have no such trouble in presenting that evidence – i.e.
> explicitly stating the nature of the evidence and how it necessarily means
> that vicariance evidence is not real evidence. I get the impression that
> chance dispersal is so obvious to you that you decline to provide the
> supporting evidence and have little patience with your viewpoint being
> challenged.
>
>
>
> As you know, I have analyzed some lizard patterns attributed to
> trans-oceanic dispersal and shown in detail that in these cases there is no
> actual evidence of dispersal and that the patterns conform to a process of
> allopatric differentiation. My arguments and evidence may be contested
> (which is fine by me), but at least I present the nature of evidence for my
> views in considerable detail.
>
>
>
> “There are presumably lots of invertebrates and plants that also show this
> pattern, but I don't have the time to delve into that.”
>
>
>
> No worries, since more assertions of your model would not add anything in
> the absence of evidence.
>
>
>
> “Vicariance does explain lots of Africa-South America relationships, but I
> still think it needs to be challenged in some cases.”
>
>
>
> Challenging vicariance is fine, but it needs evidential argument, not just
> assertions or, as in the literature, misrepresentations of the fossil
> record of calibrated molecular estimates.
>
>
>
> “Anyway, if you want answers to all your questions about such hypotheses,
> you should stop calling the answers fairy tales. I was not surprised when
> Jason said: "None of this is a fairy tale, pseudoscience nor an attack on
> vicariance."
>
>
>
> I can stop calling them fairly tales when they are sequentially connected
> to evidence and that evidence is shown to falsify vicariance. At this point
> all I see are assertions without evidence, or artificially created evidence
> (molecular divergence that is not correctly presented as minimums).
> Actually whether I consider them fairly tales or not is neither here nor
> there. Some critics have characterized panbiogeographic reconstructions in
> a similar manner. It does not matter. In science (as I understand it) the
> issue is always about the presentation and nature of what constitutes
> evidence. This seems to me to be as true for a laboratory experiment as it
> does for historical reconstruction.
>
>
>
> John Grehan
>
>
> On Thu, Jun 7, 2018 at 9:31 AM, Kenneth Kinman <kinman at hotmail.com<mailto:
> kinman at hotmail.com>> wrote:
>
> John,
>
> I do not object to vicariance (it explains many distribution
> patterns). I just think panbiogeographers tend to overdo vicariance, and
> you in particular have a tendency to start ranting when vicariance is
> challenged in some cases. So I probably won't be doing any more posts on
> the subject.
>
> I will just close by saying that there seems to be a pattern of
> Africa to South America transoceanic dispersal which also includes
> caviomorph rodents, the hoatzin, and lots of different small reptiles
> (amphisbaenians, geckos, skinks, lizards, and blind snakes). So the New
> World monkeys would not be an isolated case. There are presumably lots of
> invertebrates and plants that also show this pattern, but I don't have the
> time to delve into that.
>
> Vicariance does explain lots of Africa-South America relationships,
> but I still think it needs to be challenged in some cases. Anyway, if you
> want answers to all your questions about such hypotheses, you should stop
> calling the answers fairy tales. I was not surprised when Jason said:
> "None of this is a fairy tale, pseudoscience nor an attack on vicariance."
>
> ------------------Ken
>
>
> ________________________________
> From: John Grehan <calabar.john at gmail.com<mailto:calabar.john at gmail.com>>
> Sent: Wednesday, June 6, 2018 10:04 PM
> To: Kenneth Kinman
> Cc: Michael Heads; Taxacom
> Subject: Re: [Taxacom] Oceanic dispersal (rafting) of mammals in particular
>
>
> Ken,
>
> What I interpret from your position is that when you think a distribution
> arose by chance dispersal then dispersal explains how they got there, and
> if dispersal occurred more than once and did not succeed we will have no
> evidence of it. And allopatry is due to competitive exclusion and sympatry
> is explained as the lack of competitive exclusion. All of this is fine as
> assertions of your personal belief and there is no falsifying that. What is
> at issue, is how you reach the dispersal conclusion in the first place, and
> for both NW primates and Nothofagus you have not explained that.
>
> Jason makes the argument that if a vicariance event to 'too much' earlier
> than the oldest fossil then it cannot be believed. I don’t know if that is
> your position or if this is your reasoning for Nothofagus and Primates.
> Perhaps you would be so good as to make an explicit statement on that? It
> would go a long way to clearing up the otherwise confusing nature of your
> objections to vicariance. I realize that you do not publish on
> biogeographic method and reasoning, but it might be helpful in general to
> better understand how your views are connected to empirical sources since
> many others may share your particular perspective.
>
> John Grehan
>
>
> On Wed, Jun 6, 2018 at 9:18 PM, Kenneth Kinman <kinman at hotmail.com<mailto:
> kinman at hotmail.com>> wrote:
>
> Well, competition between primate groups in Madagascar and America
> would have only been the deciding factor if there were later oceanic
> dispersals, as in Madagascar after lemurs had become so well-established in
> many different ecological niches. Either way (later dispersals or not),
> the lack of overlap is primarily due to the ocean barriers which are very
> difficult to cross. Without ocean barriers, overlap seems to be primarily
> due to noctural vs. diurnal.
>
>
> It is somewhat similar in the case of Carnivora. In Madagascar you
> only have Family Eupleridae, and any subsequent dispersals of the related
> Family Herpestidae would have been prevented by competitive exclusion.
> Elsewhere, the Herpestidae can overlap geographically with Viverridae,
> because Herpestids are primarily terrestrial and diurnal, while Viverrids
> are primarily arboreal and nocturnal.
>
> -------------Ken
>
> ________________________________
> From: Michael Heads <m.j.heads at gmail.com<mailto:m.j.heads at gmail.com>>
> Sent: Wednesday, June 6, 2018 7:28 PM
> To: Kenneth Kinman
> Cc: Taxacom
> Subject: Re: [Taxacom] Long-distance oceanic dispersal (rafting) of
> Nothofagus species
>
> you explain the lack of overlap between the two primate clades in
> Madagascar and America by competition, but the overlap in Africa and Asia
> by a lack of competition. How does that work?
>
> On Thu, Jun 7, 2018 at 11:59 AM, Kenneth Kinman <kinman at hotmail.com
> <mailto:kinman at hotmail.com><mailto:kinman at hotmail.com<mailto:kinman@
> hotmail.com>>> wrote:
>
> Michael,
>
> (1) I've already explained the probable reason that Haplorhines are
> absent from Madagascar. Lemur ancestors got their first, radiated into
> all the available niches (which are quite varied), and competitive
> exclusion would have prevented any later haplorhine dispersals from
> becoming established (if there were any).
>
> (2) The same is probably true for the absence of Strepsirrhines from
> America. Haplorhines just dispersed there first.
>
> (3) And finally, the overlap of the two groups in much of Africa and
> Asia is probably because where they do overlap geographically, the
> Strepsirrhines are usually noctural and the Haplorhines are usually
> diurnal. The only times they might be active at the same time would be
> around dusk and dawn.
>
> ----------------Ken
>
> P.S. As for the two butterfly sister groups, butterflies wouldn't be
> killing rival intruders coming into their territories. Primates on the
> other hand can be quite vicious if a rival competitor invades their
> territory. The same is true for Carnivora.
>
> ________________________________
> From: Michael Heads <m.j.heads at gmail.com<mailto:m.j.heads at gmail.com
> ><mailto:m.j.heads at gmail.com<mailto:m.j.heads at gmail.com>>>
> Sent: Wednesday, June 6, 2018 5:49 PM
> To: Kenneth Kinman; Taxacom
>
> Subject: Re: [Taxacom] Long-distance oceanic dispersal (rafting) of
> Nothofagus species
>
> How do you explain the example I mentioned - two butterfly sister groups
> with partial overlap? This is a very common type of pattern.
>
> The monkeys (discussed at length in my 'Tropics' book and in Zool.
> Scripta. 39: 107. 2010) are another example of this:
>
> Haplorhines (monkeys etc.): America, Africa, Asia (not Madagascar).
> Strepsirrhines (lemurs etc.): Africa, Madagascar, Asia (not America).
>
> Competitive exclusion doesn't explain the absences in America and
> Madagascar, as the two groups overlap extensively through Africa and Asia.
> [https://ssl.gstatic.com/ui/v1/icons/mail/images/cleardot.gif]
>
> On Thu, Jun 7, 2018 at 10:25 AM, Michael Heads <m.j.heads at gmail.com
> <mailto:m.j.heads at gmail.com><mailto:m.j.heads at gmail.com<mailto:m.j.
> heads at gmail.com>>> wrote:
> How do you explain the example I mentioned - two butterfly sister groups
> with partial overlap? This is a very common type of pattern.
>
> The monkeys (discussed at length in my 'Tropics' book and in Zool.
> Scripta. 39: 107. 2010) are another example of this:
>
> Haplorhines (monkeys etc.): America, Africa, Asia (not Madagascar).
> Strepsirrhines (lemurs etc.): Africa, Madagascar, Asia (not America).
>
> Competitive exclusion doesn't explain the absences in America and
> Madagascar, as the two groups overlap extensively through Africa and Asia.
>
> On Thu, Jun 7, 2018 at 9:58 AM, Kenneth Kinman <kinman at hotmail.com<mailto:
> kinman at hotmail.com><mailto:kinman at hotmail.com<mailto:kinman at hotmail.com>>>
> wrote:
>
> Competitive exclusion as it relates to oceanic dispersal does not
> have to be between groups that are that closely related. It perhaps
> explains why there are no monkeys in Madagascar. The lemur ancestor
> dispersed to Madagascar first. If any monkeys dispersed to Madagascar
> later, they would have found all their niches filled by well-established
> lemurs.
>
> And likewise, lemurs may have dispersed back into mainland Africa,
> but if they did, they would have found their niches already filled by
> monkeys. So many monkeys that the lemur invaders would probably be killed
> by them.
>
> So your question "why only once" is answered. It probably wasn't
> only once. There are probably lots of cases with multiple dispersals of a
> group, but only the first to disperse became well-established, and small
> numbers of later dispersers simply died very soon after arriving. They
> would have left no evidence of their dispersal.
>
> ---------------Ken
>
> ________________________________
> From: Michael Heads <m.j.heads at gmail.com<mailto:m.j.heads at gmail.com
> ><mailto:m.j.heads at gmail.com<mailto:m.j.heads at gmail.com>>>
> Sent: Wednesday, June 6, 2018 4:18 PM
> To: Kenneth Kinman
> Cc: Taxacom
>
> Subject: Re: [Taxacom] Long-distance oceanic dispersal (rafting) of
> Nothofagus species
>
> the competitive exclusion idea only works if the clades are allopatric. In
> many cases two groups overlap in large parts of their range. For example,
> the Polyura 'eudamippus group' of butterflies: China to Sumatra and
> Borneo; P. 'pyrrhus group':Sumatra (not Borneo) to SE Australia and Fiji.
> The two groups overlap through Sumatra.
>
> On Thu, Jun 7, 2018 at 5:26 AM, Kenneth Kinman <kinman at hotmail.com<mailto:
> kinman at hotmail.com><mailto:kinman at hotmail.com<mailto:kinman at hotmail.com>>>
> wrote:
>
> Hi Jason,
>
> Excellent post. Regarding Michael's "why only once" argument, I
> would only add that I have provided another explanation in a post back in
> 2012. Namely: competitive exclusion, where the first dispersal is so
> successful that it fills all the niches for that animal or plant. If
> another dispersal happens millions of years later, they usually can't
> compete with the already well-established populations of its relative.
>
> Here is a quote from the end of my posting on 01 January 2012:
>
> "In view of John's criticisms, it should be remembered that dispersal
> ability certainly does not ensure that oceanic dispersals will be
> successful in most cases. Being able to disperse long distances is only the
> first step, but lack of suitable habitat, and more importantly competitive
> exclusion by other taxa already well-established, are obviously barriers to
> even good dispersers being automatically spread geographically. Such
> arguments against dispersalist hypotheses are therefore unconvincing
> (perhaps simple, but perhaps too often simplistic)."
>
> Here's a weblink to that post: http://mailman.nhm.ku.edu/
> pipermail/taxacom/2012-January/121575.html
>
>
> -------------Ken
>
>
> ________________________________
> From: Taxacom <taxacom-bounces at mailman.nhm.ku.edu<mailto:taxacom-bounces@
> mailman.nhm.ku.edu><mailto:taxacom-bounces at mailman.nhm.ku.edu<mailto:
> taxacom-bounces at mailman.nhm.ku.edu>>> on behalf of JF Mate <
> aphodiinaemate at gmail.com<mailto:aphodiinaemate at gmail.com><mailto:
> aphodiinaemate at gmail.com<mailto:aphodiinaemate at gmail.com>>>
> Sent: Wednesday, June 6, 2018 11:23 AM
> To: Taxacom
> Subject: Re: [Taxacom] Long-distance oceanic dispersal (rafting) of
> Nothofagus species
>
> John,
>
> analyzing biogeographic distributions is not very useful in the
> absence of a time scale. Timing is often the only difference between
> dispersal and vicariance, and all the arguments I can recall revolve
> around the absolute or relative timing of splits of one lineage vs
> another and/vs tectonics. That is why I think you focus so much on the
> only proxy we have to complete the extremely patchy fossil record.
> In the particular case of the Platyrrhini, the available evidence
> suggests that the age for the group is c. 25-32mya
> (https://doi.org/10.1093/molbev/msg172) and this is the most widely
> accepted date (give or take but close to this range) using well
> accepted molecular dating methods and fossils. You can quibble about
> fossils and calibrations if the window was small enough, but the gap
> is a chasm considering what you would need for the alternate scenario,
> so we can only conclude, based on the available evidence at hand, that
> the NW monkeys arrived there over sea and not as a result of
> vicariance. Should fossils be found at a later date that push the
> origin back sufficiently to consider the latter scenario then great,
> but so far this is not the case. If they made it there swimming,
> rafting or island-hopping (all three possible perfectably reasonable
> dispersal mechanisms) is a matter of testing the ability of these
> monkeys to survive each of these scenarios. None of this is a fairy
> tale, pseudoscience nor an attack on vicariance.
>
> This sort of dovetails with Michael´s often repeated question of "why
> only once". My answer is because dispersal is hard, unplanned and the
> chances of success slim to nil.
>
>
> Jason
>
>
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> Nurturing Nuance while Assaulting Ambiguity for 31 Some Years, 1987-2018.
>
--
Dunedin, New Zealand.
My books:
*Biogeography and evolution in New Zealand. *Taylor and Francis/CRC, Boca
Raton FL. 2017.
https://www.routledge.com/Biogeography-and-Evolution-in-New-Zealand/Heads/p/book/9781498751872
*Biogeography of Australasia: A molecular analysis*. Cambridge University
Press, Cambridge. 2014. www.cambridge.org/9781107041028
*Molecular panbiogeography of the tropics. *University of California Press,
Berkeley. 2012. www.ucpress.edu/book.php?isbn=9780520271968
*Panbiogeography: Tracking the history of life*. Oxford University Press,
New York. 1999. (With R. Craw and J. Grehan).
http://books.google.co.nz/books?id=Bm0_QQ3Z6GUC
<http://books.google.co.nz/books?id=Bm0_QQ3Z6GUC&dq=panbiogeography&source=gbs_navlinks_s>
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