Taxacom: [iczn-list] Meier et al.'s re-analysis of the data in Sharkey et al.’s (2021) in Cladistics

[Richard Zander]

Molecular analysis has fatal problems.

It relies on the assumption that one species has one molecular lineage; there are an average of 3.5 molecular races in the group I study, and each can generate new morphospecies on its own, generating molecular paraphyly and polyphyly. No, the extra races don't go away with time.

Ever wonder why ecologists tout the 30 samples rule? This is because the bell-shaped curve of a simple distribution contains 95% of variation at the inflection where the curve bends outwards (2 sigma), which is 19/20 of the variation. How do you ensure that you are sampling the rare variation occurring in 1/20 of the distribution:  sample a goodly bit more than 20, say maybe 30 samples. How many samples do molecular people make of their testing? Are the results replicable?

For progenitors with multiple descendants, each descendant is paired with a molecular race of the progenitor with exactly the same tracking traits. Where are they in a molecular cladogram? Extinct? Unsampled? Epistemologically cancelled?

Cladistics cannot detail ancestors, yet ancestor species can be quite obvious when you polarize morphospecies with an outgroup. New species that are proposed based on faulty premises, poor sampling, and lacking an evolutionary context are exercises in futility. Scientists stand on the work of others, and molecular analysis, except for the most egregious problems in taxonomy, is a rickety platform for prediction of evolution-powered changes during the sixth extinction event.
________________________________
From: Taxacom <taxacom-bounces at lists.ku.edu> on behalf of David Campbell via Taxacom <taxacom at lists.ku.edu>
Sent: Tuesday, April 19, 2022 6:47 PM
Cc: taxacom <taxacom at mailman.nhm.ku.edu>
Subject: Re: Taxacom: [iczn-list] Meier et al.'s re-analysis of the data in Sharkey et al.’s (2021) in Cladistics

>
>
> At least in
> vertebrates this gene and the mitochondria in general is affected by
> introgression. Species boundaries are unfortunately not as clean as we
> would hope. I would imagine the same may be true of many invertebrate taxa
> and even plants.


Noting some additional problems:  A few vertebrates, lots of plants, and
certain invertebrates are allopolyploids, requiring use of nuclear
markers.  Some taxa have anomalous sequences (e.g.,
https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Fonlinelibrary.wiley.com%2Fdoi%2F10.1111%2Fzsc.12139&data=05%7C01%7Ctaxacom%40lists.ku.edu%7C5de7d254ce054de2cc9008da22cebd88%7C3c176536afe643f5b96636feabbe3c1a%7C0%7C0%7C637860568746445444%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=7L8FJlAf3bxCdY9F1WAm0LvSwWu2Ce57GSLBomND7%2Bc%3D&reserved=0).  Symbionts can be a
problem (https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Facademic.oup.com%2Fsysbio%2Farticle%2F58%2F4%2F445%2F1681303&data=05%7C01%7Ctaxacom%40lists.ku.edu%7C5de7d254ce054de2cc9008da22cebd88%7C3c176536afe643f5b96636feabbe3c1a%7C0%7C0%7C637860568746445444%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=ROOG1QfjQaMLDW3B47fRUh6J770fSikosa5lSlWCvxM%3D&reserved=0), as are
misidentifications of reference sequences.
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