[Taxacom] Jurassic primates???

[Kenneth Kinman]

Michael,

      Your 2010 paper proposes that Old World monkeys and New World monkeys split about 130 million years ago.  That age more than doubles what most mammalogists would accept as likely.  And your estimate of about 185 million years ago for the origin of Primates is roughly triple the generally accepted age.

      And fossil primates can be identified by mere scraps of different parts of their skeleton, and the morphology of their various teeth have been intensely studied.  But I guess you really believe that there were Jurassic and Early Cretaceous primates and that somehow noone has ever found even a scrap of their skeletons in the fossil record between 185 and 65 million years ago.

       Extraordinary claims require extraordinary evidence, and Goswami and Upchurch provide many reasons for doubting your extraordinary claims.  They didn't call your hypothesis a "fairy tale", but I suspect they probably would have liked to do so.  They were just too polite.

       I would be interested to know if anyone subscribed to Taxacom (besides Michael Heads and John Grehan) find the hypothesis in Heads 2010 paper at all convincing.


Heads, 2010:  https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1463-6409.2009.00411.x


Reply by Goswami and Upchurch, 2010: https://www.researchgate.net/publication/229977172_The_dating_game_A_reply_to_Heads_2010



________________________________
From: Taxacom <taxacom-bounces at mailman.nhm.ku.edu> on behalf of Kenneth Kinman <kinman at hotmail.com>
Sent: Tuesday, June 12, 2018 7:10 PM
To: Michael Heads
Cc: Taxacom
Subject: Re: [Taxacom] Oceanic dispersal vs. vicariance

Hi Michael,

        I cannot imagine transoceanic dispersal on an actual floating island with cliffs.   However, a huge floating raft composed of many hundreds of trees and soil clinging to the roots of those which were upside down seems very possible.  So I view some of the anti-vicariance views of Alan de Queiroz as being a bit extreme.

       On the other hand, I would tend to agree with Goswami and Upchurch, 2010, in arguing against Heads, 2010:

"Heads (2010) argued for the use of continental break-up dates as calibration points for molecular clocks when the taxon of interest is widely distributed but dispersal across open oceans is considered improbable.  Using this method, he estimated that the placental mammal clade Primates originated in the Early Jurassic, requiring a 130 million year ghost lineage before the first euprimate fossils appear in the record. We demonstrate that this argument is flawed for several reasons."
       I cannot imagine ever finding primate fossils in the Early Jurassic (or even the Early Cretaceous).  I assume John Grehan would probably argue for such early primates, but I just can't imagine such a long ghost lineage as being likely.  I can see rodents living underground (perhaps hibernating for an extended period) surviving the Cretaceous-Paleocene extinction event, but not primates.
       Anyway, as I said before, there seem to be some extreme views on both sides of the debate over vicariance vs. transoceanic dispersal.   And the truth is very likely in between, and I reject such extremes on both sides of the debate.
                            ------------------Ken
P.S.  Here is a weblink to the abstract of Goswami and Upchurch, 2010:  <https://www.researchgate.net/publication/229977172_The_dating_game_A_reply_to_Heads_2010> https://www.researchgate.net/publication/229977172_The_dating_game_A_reply_to_Heads_2010



________________________________
From: Michael Heads <m.j.heads at gmail.com>
Sent: Monday, June 11, 2018 5:43 PM
To: Kenneth Kinman
Cc: Taxacom
Subject: Re: [Taxacom] Oceanic dispersal vs. vicariance

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<mailto: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