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@dbarclay @redgarter Thoughts on this swap?

Posted by thomaseverest almost 3 years ago

Lumpers will lumps. I'm no taxonimist ot geneticist, but I am always suspicious when such broad lumping is done on the sole basis of mtDNA analysis. The Southern Mapleleaf doesn't get all those extra pustules all over it's sulcus from it's mitocohondrial DNA, it gets them from it nuclear (nucular if you're Republican) DNA . But since analyzing that is way more expensive, most phylogenetic studies are done with mtDNA, hence the shortcomings and doubt. And when I read this sort of stuff, I wonder whatever happened to to notion of sub-species?, or species complexes? I should read more sciency stuff, but it's more fun to muck around looking for - highly variable phenotypes of - critters.

Posted by redgarter almost 3 years ago

Alright I'll leave as a draft for now. You're correct that they don't have much analysis of anything other than DNA. They briefly mention shape and range, but not sculpture which seems odd to me. Subspecies and species complexes would require distinct clades, which doesn't seem to be the case according to this paper (Q. quadrula is paraphyletic). And yes, whole genome sequencing would be nice to have. :) Mitochondrial analysis does have the benefit of (generally) having a constant mutation rate in cytochrome b.

Posted by thomaseverest almost 3 years ago

Thanks Thomas. Will have to read up on clades and paraphyletics on a rainy day in the near future!

Posted by redgarter almost 3 years ago

I do recall seeing a graphic (I assume in another paper?) that showed how the shell variation in the Q. quadrula complex appeared to be clinal. I'll see if I can find that...

Posted by amr_mn over 2 years ago

I found it, it's "A taxonomic study of Quadrula quadrula (Rafinesque)" by J.K. Neel, from 1941.
PDF available.
http://hdl.handle.net/2027.42/56887

It did place Q. fragosa in with Q. quadrula quadrula.
It also placed T. nobilis in with Q. quadrula apiculata (perhaps due to Conrad's own mixed collection in the original paper).

Posted by amr_mn over 2 years ago

Thanks! Sorry for my late response. It does say that tubercles/pustules are generally distinct and geographically isolated in Q. apiculata, but that that is also highly variable and there are intergrades to Q. quadrula sensu stricto. Given the genetic evidence I think I'll go ahead with the merge here and elsewhere if there are no objections. Best to stay in line with MB anyway.
https://www.inaturalist.org/taxon_merges/92562

Posted by thomaseverest over 2 years ago

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