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Taxacom: supposed evidence of Pacific ignuana dispersal

Geoff Read gread at actrix.gen.nz
Sat Mar 22 03:44:16 CDT 2025 

No Michael, they don't "just say" that.  There is extensive discussion
including of a Eurasian etc origin and they seem to cover every prior
hypothesis.Don't go way up the classification.  Do that and anything is a
possibility.Down at the subfamily level of Iguaninae their work links
Fijian species Brachylophus bulabula in a clade with Dipsosaurus dorsalis
of the Southwestern United States and northwestern Mexico. And the other
iguanas nearby in their tree are N. American, Galapagos, and Antilles.The
tree as published is the salient part, not the full tree, which would be
nice to see - apparently that is in the supplementary data.
Geoff

--
Geoffrey B. Read, Ph.D.
Wellington, NEW ZEALAND
gread at actrix.gen.nz

---- Original Message ----
From: Michael Heads 
To: "Geoff Read" 
Cc: "taxacom" 
Sent: Sat, Mar 22, 2025, 5:27 PM
Subject: Re: Taxacom: supposed evidence of Pacific ignuana dispersal

  They just say: 'Pleurodonta = Iguanidae sensu ( 16 ) (e.g., anoles,
horned lizards, and relatives), are also largely restricted to the western
hemisphere'.  They don't mention the sister group, let alone vicariance
with it, although it's a classic case of vicariance that's been cited many
times. 
      Pleurodonta: Madagascar + Americas + Fiji/Tonga. (i..e trans-Pacific
+ Atlantic).
      Acrodonta (sis group of Pleurodonta): Madagascar + Africa + Europe +
Asia to Australia and Solomons. (Trans-Indian).
The groups are allopatric except in Madagascar. The distributions are
determined by breaks (of a global ancestor) in the Atlantic, around
Madagascar, and between the Solomons and Fiji, all areas of major rifting.
There is no dispersal indicated except (perhaps) in Madagascar. 
On Sat, Mar 22, 2025 at 12:26?PM Geoff Read via Taxacom  wrote:
 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%7C16d87ff84f984853b81208dd691dc7a5%7C3c176536afe643f5b96636feabbe3c1a%7C0%7C0%7C638782299277349061%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C40000%7C%7C%7C&sdata©JVfWdEq7YjNLI01oXaZLYQHwQtuvOFhedgXDlXtpc%3D&reserved=0
(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%7C16d87ff84f984853b81208dd691dc7a5%7C3c176536afe643f5b96636feabbe3c1a%7C0%7C0%7C638782299277366299%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C40000%7C%7C%7C&sdata=TB31uSBK0a5x45jCFZTPxL49O%2BySAc1YG9MvflKXd%2Bw%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 (mailto:gread at actrix.gen.nz)
 >---- Original Message ----
 >From: John Grehan via Taxacom 
 >To: "taxacom" 
 >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%7C16d87ff84f984853b81208dd691dc7a5%7C3c176536afe643f5b96636feabbe3c1a%7C0%7C0%7C638782299277377748%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C40000%7C%7C%7C&sdata=VirC8Fqy9dwivyWLLiPRbJB%2FQHRBPcAtd65A2tbo2rk%3D&reserved=0
(https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdoi.org%2F10.1073%2Fpnas.2318622122&data%7C02%7Ctaxacom%40lists.ku.edu%7C16d87ff84f984853b81208dd691dc7a5%7C3c176536afe643f5b96636feabbe3c1a%7C0%7C0%7C638782299277389213%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C40000%7C%7C%7C&sdata=toXE%2BFLlygv0kbQwFdBlY2kCqYoxFruJq4XvXCdbbLI%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
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My books:
	Biogeography and evolution in New Zealand. Taylor and Francis/CRC, Boca
Raton FL. 2017. 
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(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%7C16d87ff84f984853b81208dd691dc7a5%7C3c176536afe643f5b96636feabbe3c1a%7C0%7C0%7C638782299277417826%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C40000%7C%7C%7C&sdataêW3M58EBfZpsmmslY%2F7N%2FlKSnnc92Y5qtGzO8eqQFo%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%7C16d87ff84f984853b81208dd691dc7a5%7C3c176536afe643f5b96636feabbe3c1a%7C0%7C0%7C638782299277429175%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C40000%7C%7C%7C&sdata=DzQHzlFBDsAcB%2F%2Bx0YkJBp24SbS%2BdG4JhN7tmDTCteI%3D&reserved=0
(https://nam10.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.cambridge.org%2F9781107041028&data%7C02%7Ctaxacom%40lists.ku.edu%7C16d87ff84f984853b81208dd691dc7a5%7C3c176536afe643f5b96636feabbe3c1a%7C0%7C0%7C638782299277440246%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C40000%7C%7C%7C&sdata=g6zTfpqPW4wm6wCUCj7lDTXooa1UtmaoFnEvNonc1Hg%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%7C16d87ff84f984853b81208dd691dc7a5%7C3c176536afe643f5b96636feabbe3c1a%7C0%7C0%7C638782299277451454%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C40000%7C%7C%7C&sdata=BMC2%2F%2BzTcDtfJO4OJPsN%2FvSrilkycABd83QKCy5xugQ%3D&reserved=0
(https://nam10.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.ucpress.edu%2Fbook.php%3Fisbn%3D9780520271968&data%7C02%7Ctaxacom%40lists.ku.edu%7C16d87ff84f984853b81208dd691dc7a5%7C3c176536afe643f5b96636feabbe3c1a%7C0%7C0%7C638782299277462772%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C40000%7C%7C%7C&sdata=X2UXdMutiEjVZUuKx4x6LhqH8KZDAp5mF8Xa6XOup1A%3D&reserved=0)
	Panbiogeography: Tracking the history of life. Oxford University Press,
New York. 1999. (With R. Craw and J. Grehan).
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