Search the Taxacom archive · Browse by month · Mirror of the former lists.ku.edu archive (1992–2025)

Taxacom: supposed evidence of Pacific ignuana dispersal

Michael Heads m.j.heads at gmail.com
Sat Mar 22 13:01:28 CDT 2025 

but why did they not even mention the simplest model - vicariance with the
sister?

On Sun, Mar 23, 2025 at 4:18?AM Kenneth Kinman via Taxacom <
taxacom at lists.ku.edu> wrote:

> Hi Geoff,
>         I agree.  This is a fine research paper.  And if iguanas can
> travel 300 km. overseas in recent times, much further voyages over millions
> of years are very probable.
>         And of all the iguanas to break a dispersal record, it is the
> desert iguana.  On land, they can survive very long periods of dehydration
> and lack of food, so doing so on a floating island of vegetation makes them
> the best suited for such a voyage.   A large island of many trees would be
> even more ideal with a source of food making survival even more likely.
>                               ------------Ken Kinman
> ________________________________
> From: Taxacom <taxacom-bounces at lists.ku.edu> on behalf of Geoff Read via
> Taxacom <taxacom at lists.ku.edu>
> Sent: Friday, March 21, 2025 6:25 PM
> To: taxacom <taxacom at mailman.nhm.ku.edu>
> Subject: Re: Taxacom: supposed evidence of Pacific ignuana dispersal
>
>
>
> Here's one of the news articles mentioned by John.
>
>
> https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Fapnews.com%2Farticle%2Figuana-fiji-raft-float-journey-travel-9732d828c28a8374a6873fbc1b3d4af2&data%7C02%7Ctaxacom%40lists.ku.edu%7Cda12464f84d54519ae7008dd696b998b%7C3c176536afe643f5b96636feabbe3c1a%7C0%7C0%7C638782633497110767%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C60000%7C%7C%7C&sdata=ut1fJIAp4MiPUiqwYCcRB3LZ8yznLLrV2ivQcJBSyNU%3D&reserved=0
>
> I've read the PNAS article and it does seem to be a very thorough
> even-handed assessment of all the possibilities in their discussion.
>
> They say humans have observed iguanas making landfall on islands and quote
> this presumably famous instance:
>
> "In 1995, a vegetation mat
> with at least 15 individual green iguanas (Iguana iguana) that likely
> originated on the islands of Guadeloupe was observed making landfall
> on Anguilla, an island 300 km away that was already inhabited by
> a different species of iguana, I. delicatissima"
>
> One quibble is that they work at a genus-level with little mention of
> species.  The genus is an 'it' as though it is a physical entity. A
> practice more familiar of palaeontologists rather than molecular biologists.
>
> This quote illustrates the style:  "Brachylophus , which contains 4 extant
> and 1 extinct species, is morphologically divergent from other iguanas and
> occurs extremely far from all of its extant relatives"
>
> Substitute 'are' for 'is' and 'their' for 'its' and see how it reads. The
> actual species is Brachylophus bulabula.  It gets just one mention (in a
> figure), and there are relations on different Fijian islands, plus
> apparently also one iguana human-transported.
>
> --
> Geoffrey B. Read, Ph.D.
> Wellington, NEW ZEALAND
> gread at actrix.gen.nz
>
>
>
> >---- Original Message ----
> >From: John Grehan via Taxacom <taxacom at lists.ku.edu>
> >To: "taxacom" <taxacom at mailman.nhm.ku.edu>
> >Sent: Fri, Mar 21, 2025, 9:33 AM
> >Subject: Taxacom: supposed evidence of Pacific ignuana dispersal
> >
> >Some of you may have seen this as it's been splashed around widely on the
> >propaganda circuit.
> >
> >Iguanas rafted more than 8,000 km from North America to Fiji PNAS 2025
> Vol.
> >122 No. 12 e2318622122 https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdoi.org%2F10.1073%2Fpnas.2318622122&data%7C02%7Ctaxacom%40lists.ku.edu%7Cda12464f84d54519ae7008dd696b998b%7C3c176536afe643f5b96636feabbe3c1a%7C0%7C0%7C638782633497134416%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C60000%7C%7C%7C&sdata=P%2FgVIJZptyMJ%2Fa8oguhaCBiwp%2FQePZe9H1Yo1YesraY%3D&reserved=0
> >
> >It's just another duplication of the same old trash. Abstract claims that
> >?Here, we investigate the occurrence and timing of the greatest known
> >long-distance oceanic dispersal event in the history of terrestrial
> >vertebrates?the rafting of iguanas from North America to Fiji.? Trouble
> >with this is that it makes out that this ?long-distance oceanic dispersal
> >event? is an established scientific fact when it is not.
> >
> >
> >Then they assert that ?Iguanas are large-bodied herbivores that are
> >well-known overwater dispersers, including species that colonized the
> >Caribbean and the Gal?pagos islands.? when there is absolutely no
> >empirically based evidence that the Galapagos iguanas ever dispersed
> >overwater to the Galapagos.
> >
> >
> >
> >And the central rot (as in decay) of their claims is the same as all the
> >other center of origin-chance dispersal recipes: The divergence estimate
> is
> >based on fossil calibration which can only render minimum ages. Anything
> >else (such as priors) is conjecture. So their timeline is erroneous in
> this
> >respect. The other is that their ancestral-areas analysis is simply a
> >recipe that cannot empirically distinguish between chance dispersal and
> >vicariance as either can generate the same phylogenetic area sequence.
> >
> >
> >
> >Given their calling attention to the Galapagos it seems an incredible
> >oversight to have missed Heads & Grehan 2021 on Galapagos biogeography,
> >including the Fiji connection. I've seen this before, where there is a
> >narrow range of citations restricted to the same school of thought.
> >Anything else does not exist. This, then, is the pinnacle of academic
> >achievement in the US (maybe a good argument for the government trashing
> >science?).
> >
> >
> >Cheers, John
>
>
> _______________________________________________
> Taxacom Mailing List
>
> Nurturing nuance while assailing ambiguity for 38 years, 1987-2025.
>
> Send Taxacom mailing list submissions to: taxacom at lists.ku.edu
> For list information; to subscribe or unsubscribe, visit:
> https://lists.ku.edu/listinfo/taxacom
> You can reach the person managing the list at: taxacom-owner at lists.ku.edu
>
>
> _______________________________________________
> Taxacom Mailing List
>
> Nurturing nuance while assailing ambiguity for 38 years, 1987-2025.
>
> Send Taxacom mailing list submissions to: taxacom at lists.ku.edu
> For list information; to subscribe or unsubscribe, visit:
> https://lists.ku.edu/listinfo/taxacom
> You can reach the person managing the list at: taxacom-owner at lists.ku.edu
>
>
>

-- 
Dunedin, New Zealand.

My books:

*Biogeography and evolution in New Zealand. *Taylor and Francis/CRC, Boca
Raton FL. 2017.
https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.routledge.com%2FBiogeography-and-Evolution-in-New-Zealand%2FHeads%2Fp%2Fbook%2F9781498751872&data%7C02%7Ctaxacom%40lists.ku.edu%7Cda12464f84d54519ae7008dd696b998b%7C3c176536afe643f5b96636feabbe3c1a%7C0%7C0%7C638782633497147738%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C60000%7C%7C%7C&sdata=jJfCIHN%2B31TLUpXDTSh5T0Bg4%2BFNz6WzUYqhfOfo56A%3D&reserved=0


*Biogeography of Australasia:  A molecular analysis*. Cambridge University
Press, Cambridge. 2014. https://nam10.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.cambridge.org%2F9781107041028&data%7C02%7Ctaxacom%40lists.ku.edu%7Cda12464f84d54519ae7008dd696b998b%7C3c176536afe643f5b96636feabbe3c1a%7C0%7C0%7C638782633497160509%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C60000%7C%7C%7C&sdata=TwB%2BDDreGZ0zZabHiCTeY6iwhHKH31cFPGkjSP3Hwac%3D&reserved=0


*Molecular panbiogeography of the tropics. *University of California Press,
Berkeley. 2012. https://nam10.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.ucpress.edu%2Fbook.php%3Fisbn%3D9780520271968&data%7C02%7Ctaxacom%40lists.ku.edu%7Cda12464f84d54519ae7008dd696b998b%7C3c176536afe643f5b96636feabbe3c1a%7C0%7C0%7C638782633497172940%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C60000%7C%7C%7C&sdata=4Z3qhSR6GfKuJFblw8VZfcPW%2FTOJEypneYkv0P4DtiM%3D&reserved=0


*Panbiogeography: Tracking the history of life*. Oxford University Press,
New York. 1999. (With R. Craw and J. Grehan).
https://nam10.safelinks.protection.outlook.com/?url=http%3A%2F%2Fbooks.google.co.nz%2Fbooks%3Fid%3DBm0_QQ3Z6GUC&data%7C02%7Ctaxacom%40lists.ku.edu%7Cda12464f84d54519ae7008dd696b998b%7C3c176536afe643f5b96636feabbe3c1a%7C0%7C0%7C638782633497185320%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C60000%7C%7C%7C&sdata=gg%2FxnUCnCIDSMBhpWFpIg42471x57IITjBt46n1cRzA%3D&reserved=0
<https://nam10.safelinks.protection.outlook.com/?url=http%3A%2F%2Fbooks.google.co.nz%2Fbooks%3Fid%3DBm0_QQ3Z6GUC%26dq%3Dpanbiogeography%26source%3Dgbs_navlinks_s&data%7C02%7Ctaxacom%40lists.ku.edu%7Cda12464f84d54519ae7008dd696b998b%7C3c176536afe643f5b96636feabbe3c1a%7C0%7C0%7C638782633497198093%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C60000%7C%7C%7C&sdata=l44AhVIMeXyFEy9ssnAepsHmIDQ9ywS3B0ioxuA0aU4%3D&reserved=0>

More information about the Taxacom mailing list