Taxacom: Phylogeny of Phylum Mollusca

[Kirk Fitzhugh]

Choice of outgroup(s) is the least of the problems with the study.

-------------------------------------------------
J. Kirk Fitzhugh, Ph.D.
Curator of Polychaetes
Research & Collections Branch
Natural History Museum of Los Angeles County
900 Exposition Blvd
Los Angeles CA 90007
Phone: 213-763-3233
e-mail: kfitzhugh at nhm.org
-------------------------------------------------


On Sun, Jul 20, 2025 at 7:21?PM Kenneth Kinman via Taxacom <
taxacom at lists.ku.edu> wrote:

> Hi All, I have been looking for recent molecular evidence regarding the
> origin and evolution of Phylum Mollusca. I found one recently published a
> few months ago (see weblink below). Unfortunately from my perspective, it
> suffers from the same
> 
>
> Hi All,
>      I have been looking for recent molecular evidence regarding the origin and evolution of Phylum Mollusca.  I found one recently published a few months ago (see weblink below).
>       Unfortunately from my perspective, it suffers from the same fundamental problem that previous studies have suffered, namely the very poor choice of outgroups.  If you include groups for outgroups which actually turn out to be ingroups to Phylum Mollusca, the phylogeny presented is automatically fatally flawed.  This has been a persistent problem ever since molecular evidence has been used (for decades) to determine the phylogeny of Phylum Mollusca.   The ancestors of Phylum Mollusca lie in some very small "shelly fauna" of the Precambrian (which are extremely poorly known), not in any Cambrian molluscs which evolved long after.
>      As I have argued previously, if inappropriate outgroups are used, the results are extremely misleading, and that it is actually "morphological evidence", not such misleading molecular conclusions, that makes more sense.   I realize this is still a minority view that Phylum Bivalvia gave rise to the other molluscan phyla, but a view that has not been evaluated properly.  The majority seem to rely on every new analysis which is again based on inappropriate outgroups.  The weblink below is just the most recently example.
>                     -------------Ken Kinman
>
>  https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Furldefense.com%2Fv3%2F__https%3A%2F%2Fwww.science.org%2Fdoi%2F10.1126%2Fscience.ads0215__%3B!!Ljrh0eb5atLX!vojQ9g1F0LGDbbMBRCE6-t2nLkikwgxSQyHDXlS3VAuGQgmEOr6BYUzERs_hMw8NzlJYVkExsg3846Xq7rU%24&data%7C02%7Ctaxacom%40lists.ku.edu%7Cbd232b361dff4848499d08ddc8093010%7C3c176536afe643f5b96636feabbe3c1a%7C0%7C0%7C638886663981210353%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata¿sxOqosO9BEnX3EtDHM5lplUTj3YjKYGoxYYw9b%2BA8%3D&reserved=0
>
>
>
>
> _______________________________________________
> 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://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Furldefense.com%2Fv3%2F__https%3A%2F%2Flists.ku.edu%2Flistinfo%2Ftaxacom__%3B!!Ljrh0eb5atLX!vojQ9g1F0LGDbbMBRCE6-t2nLkikwgxSQyHDXlS3VAuGQgmEOr6BYUzERs_hMw8NzlJYVkExsg38MG34pkc%24&data%7C02%7Ctaxacom%40lists.ku.edu%7Cbd232b361dff4848499d08ddc8093010%7C3c176536afe643f5b96636feabbe3c1a%7C0%7C0%7C638886663981269822%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=YwO7ykm1DNgeqXttkxallrZZeutsNaLHwjjb2jd8iqU%3D&reserved=0
> You can reach the person managing the list at: taxacom-owner at lists.ku.edu
>
>