[Taxacom] Oceanic dispersal vs. vicariance
John Grehan
calabar.john at gmail.com
Sun Jun 17 21:45:42 CDT 2018
Hi Ken, That's your privilege. No one had to like how I respond. Your
choice. Sometimes I don't like the way you say things either, but I ignore
that as irrelevant and do the best I can to respond. Such responses may not
always meet the desires of the recipient, but that's life (and science).
Cheers, John Grehan
On Sun, Jun 17, 2018 at 10:24 PM, Kenneth Kinman <kinman at hotmail.com> wrote:
> Hi Jason,
>
> I agree. Your description "instead it all ends in a series of
> zingers written in scripted, telegraphic style" would pretty much describe
> my views of John's polemics in particular. Especially when his zingers
> involve creationists or Hitler Thus my reluctance to respond to most of
> his e-mails. I think I will now answer Michael's post instead.
>
> ------------------- Ken
>
>
>
> ________________________________
> From: Taxacom <taxacom-bounces at mailman.nhm.ku.edu> on behalf of JF Mate <
> aphodiinaemate at gmail.com>
> Sent: Sunday, June 17, 2018 8:41 PM
> To: Taxacom
> Subject: Re: [Taxacom] Oceanic dispersal vs. vicariance
>
> John, Michael, this isn´t going anywhere. I was waiting for a hint of
> proper debate but instead it all ends in a series of "zingers" written
> in scripted, telegraphic style. I have not seen any ideas presented by
> either one of you that aren´t encapsulated and operationalized in a
> superior manner in cladistic biogeography or evolutionary
> biogeography, sans the unproven axiomatic mania that dispersal doesn´t
> occur. In fact, you don´t seem to to agree on a definition of
> dispersal or if it even occurs (Michael says he doesn´t question
> "slight" dispersal, but you say otherwise). To move the debate towards
> some clear definition of dispersal, I would point to present day,
> observable examples such as Inachis io crossing from Europe to NA or
> Danaus plexippus going the other way. To me these are clear, working
> examples of dispersal, some successful (D. plexippus) others, like
> Inachis io, failing time after time. Neither is a slight jump Please
> think about this carefully before replying.
>
> In regards to the dung beetle fauna of Madagascar, we first have to
> consider the fossil evidence. The oldest known Scarabaeinae fossil is
> of unknown affinity (Prionocephale deplanate, U Cretaceous; Krell,
> 2007). Between this assumed Scarabaeinae fossil and clearly
> identifiable ones we have to jump to the Palaeocene-Miocene, where we
> find ichnofossils (brood balls). This in itself is interesting because
> they are the sort of easily preserved structures we should expect to
> commonly find (actually common in paleosols in SA), but we don´t in
> older deposits, so we must assume that they were either uncommon or
> nonexistent. This doesn´t mean that Scarabaeinae were not found then
> but that lineages that build deep nests with brood balls evolved after
> the K-T. These lineages are also found in Madagascar nowadays
> (Helictopleurus, Onthophagus, Scarabaeus) so their presence there is
> difficult to reconcile with a purely vicariant model, even without
> considering the phylogenetic evidence which have them evolving in the
> Palaeocene.
>
> The Malagasy genera endemic genera (except Onthophagus) that have been
> studied yield the following date estimates:
>
> Arachnodes, Epilissus & Apterepilissus 79-49my
> Nanos & Apotolamprus 24-15my (Wirta, Helena. (2018). Dung beetle
> radiations in Madagascar. )
> Epactoides 30-19my
> Helictopleurus 37-23 (doi.org/10.1016/j.ympev.2008.03.010)
> Scarabaeus 24-15my
> Onthophagus: >3 colonizations (age of entire Onthophagini lineage,
> Palaeocene)
> doi:10.3390/insects2020112
> doi.org/10.1111/j.1096-0031.2006.00139.
>
>
> The Aphodiiinae presents more complex biogeography. The oldest fossil
> (a generalized "aegialid-like" genus from the Lower Cretaceous,
> Cretaegialia) suggests a window that may enable some of the lineages
> to be Gondwanan. However, the "coprophilous" Aphodiini are generally
> assumed to be Laurasian in origin (incorrectly in my opinion but we
> have to refer to the published studies). This in itself, plus their
> assumed recent origin ( <60my; DOI: 10.1016/j.ympev.2003.10.019; the
> oldest fossil evidence is Miocene.), makes it almost impossible for
> the lineage to have been present in Madgascar before its split from
> Gondwana.
> At the level of the subgenera that exist in Madagascar, most of them
> are shared with Africa, even down to species:
>
> Nonendemic subgenera: Aganocrossus (1 nonendemic sp); Blackburneus (2
> nonendemic sp); Koshantschikovius (4 endemic sp); Paradidactylia (1
> endemic sp); Pleuraphodius (1 endemic sp, 1 nonendemic sp);
> Pharaphodius (1 nonendemic sp, 2 endemic sp); Pseudopharaphodius (1
> nonendemic sp); Labarrus (2 nonendemic sp; 1 tramp; 1 endemic sp);
> Mesontoplatys (2 nonendemic sp); Neocalaphodius (1 nonendemic sp);
> Nialaphodius (2 nonendemic sp).
>
> Endemic Malagasy subgenera: Madagaphodius (1 sp); Neoemadiellus (8 sp).
>
> Bordat, Paulian & Pittino 1990
>
> The other Aphodiinae tribes have varying degrees of endemicity that
> suggest vicariance for some (e.g. Saprosites, Aulonocneminae/i) or
> dispersal for others (Rhyparini). I believe the above examples are
> sufficient to illustrate the point.
>
> Best
>
> Jason
>
> On 12 June 2018 at 23:09, Michael Heads <m.j.heads at gmail.com> wrote:
> > Jason,
> > You write: ''... it seems that we can all more or less agree that
> timing is
> > the key difference between both mechanisms, and in that context
> patterns in
> > themselves can´t distinguish either mechanism, so they are not
> informative
> > in this specific instance and we can dispense with tracks
> > and other such pattern searching'.
> >
> > Of course, you are free to ignore distributions if you like. But here is
> > what the author of the most cited bbiogeographic work had to say:
> >
> > "To do science is to search for repeated patterns, not simply to
> accumulate
> > facts, and to do the science of geographical ecology is to search for
> > patterns of plant and animal life that can be put on a map". (MacArthur,
> > 1972: 1).
> >
> > On Wed, Jun 13, 2018 at 8:21 AM, JF Mate <aphodiinaemate at gmail.com>
> wrote:
> >>
> >> Sorry to all for dropping off the map. In particular apologies to Ken
> >> for leaving him steadfastly defending the fort on his own. Anyway, it
> >> seems that we can all more or less agree that timing is the key
> >> difference between both mechanisms, and in that context patterns in
> >> themselves can´t distinguish either mechanism, so they are not
> >> informative in this specific instance and we can dispense with tracks
> >> and other such pattern searching.
> >>
> >> So when you claim that “... much of the opposition on timing comes
> >> from rejection of tectonic correlations that are earlier than the
> >> (minimum) molecular estimates.” you are mistaken. The problem is that
> >> if the timing is not in agreement with the tectonic evidence then
> >> vicariance can no longer be a contender for the time being. This is
> >> not a rejection of vicariance but a simple observation that the
> >> evidence available just isn´t´t in agreement and dispersal must be
> >> considered as likely.
> >>
> >> Saying that “To me this is about as feeble as it gets with
> >> biogeography - that dispersal occurred more than once but left no
> >> evidence. But it happened more than once for sure.” is semantic
> >> footplay posing as scientific rigour. There are limitations and these
> >> have always been acknowledged by molecular taxonomists from the
> >> beginning, but not to be used as an underhanded, semantic mallet to
> >> clobber dissent. And therein lies the issue I have with you and
> >> Michael. Nobody is questioning vicariance, you question dispersal. So
> >> really, we only need one example of dispersal to invalidate your
> >> epistemological building and that is pushing you to make semantics
> >> your arena with such choice examples as “I do not complain about
> >> molecular estimates of divergence, I only complain about minimums
> >> being misrepresentated as actual or maximal. There is a difference!”
> >> or “It only involves the Big Lie about molecular estimates.” Quacks
> >> like a duck and all that.
> >>
> >> You also try to distract the argument by introducing other groups that
> >> were not part of the initial discussion. Neither vicariance nor
> >> dispersal are on trial here. They are both generally accepted
> >> mechanisms (except by you two it seems) and the only question
> >> originally posed was, which had a hand in the Platyrrhini, so let´s go
> >> back to the Platyrrhini. The available evidence, the research on this
> >> topic, is pretty much in agreement with Ken´s assertion. What do you
> >> bring to the table to refute this. Claiming that “One can only assert
> >> otherwise by the Große Lüge that fossil calibrated molecular estimates
> >> are not minimums.” is pure semantics. The burden of proof is with you
> >> providing fossil evidence or a new dataset that, when calibrated,
> >> contradicts the previous studies.
> >>
> >> Ken also mentions the Malagasy fauna as having recent elements that
> >> precede its split from Gondwana, and he is correct in this regard as
> >> well. There are truly ancient lineages that are vicariant but much
> >> more recent ones that cannot have arrived by means other than
> >> dispersal (e.g. The dung beetle fauna is a combination). That is my
> >> bit of evidence. If you can provide counterfactual evidence that can
> >> be profitably discussed then that would be great. Semantics not so
> >> much.
> >>
> >> Have a good one.
> >>
> >> On 11 June 2018 at 05:26, John Grehan <calabar.john at gmail.com> wrote:
> >> > Hi Ken,
> >> >
> >> > My comments below.
> >> >
> >> > “ 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. “
> >> >
> >> >
> >> >
> >> > There is no evidence that the ‘truth’ is ‘probably’ somewhere
> inbetween.
> >> >
> >> >
> >> >
> >> > “ Perhaps the strongest case for a large number of oceanic dispersals
> is
> >> > probably from the African mainland to Madagascar. “
> >> >
> >> >
> >> >
> >> > What is the purported evidence?
> >> >
> >> >
> >> >
> >> > “but there is apparently evidence that some of those dispersals were
> >> > along
> >> > island chains that no longer exist.”
> >> >
> >> >
> >> >
> >> > What is the purported evidence?
> >> >
> >> >
> >> >
> >> > “Whether such islands existed or not,”
> >> >
> >> >
> >> >
> >> > Then there is no actual evidence?
> >> >
> >> >
> >> >
> >> > “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). “
> >> >
> >> >
> >> >
> >> > That comes across as a misrepresentation (unintentional I am sure). I
> do
> >> > not complain about molecular estimates of divergence, I only complain
> >> > about
> >> > minimums being misrepresentated as actual or maximal. There is a
> >> > difference!
> >> >
> >> >
> >> >
> >> > “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). “
> >> >
> >> >
> >> >
> >> > Then state what is the purported evidence. No good just saying so.
> >> >
> >> >
> >> >
> >> > “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,”
> >> >
> >> >
> >> > It only involves the Big Lie about molecular estimates.
> >> >
> >> >
> >> >
> >> > “but also whether or not New Zealand was completely submerged at some
> >> > time
> >> > in the mid Cenozoic.”
> >> >
> >> >
> >> >
> >> > This never had legs to begin with and has been generally buried by
> >> > geologists and even orthodox biogeographers.
> >> >
> >> >
> >> >
> >> > “ 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. “
> >> >
> >> > If there is evidence for rafting then sure, consider it.
> >> >
> >> >
> >> >
> >> > “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 is not a ‘Gondwana’ group.
> >> >
> >> >
> >> >
> >> > “Nothofagus distribution could be due to a combination of both
> >> > vicariance
> >> > and some cases of more recent oceanic dispersal.”
> >> >
> >> > Or not. But panbiogeography shows clearly that such a combination does
> >> > not
> >> > have to be invented.
> >> >
> >> >
> >> > John Grehan
> >> >
> >> >
> >> > On Sun, Jun 10, 2018 at 10:25 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
> >> >>
> >> >>
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