Kuhl et al. 2020: an ‘unbiased, resolved’ avian tree of life?

Similar to other traditional myths,
Kuhl et al. 2020 repeat a traditional myth that will never be validated.

From the abstract
“In this tree, grebes and flamingos are the sister clade of all other Neoaves,”

Kuhl et al. is a genomic study. These two bird types do not resemble each other (Fig. 1) and do not nest together in phenomic studies, like the large reptile tree (LRT, Subset Fig. 2). Prum et al. 2015 recovered the same false positive relationship. If a study cannot be validated by traits, it is invalid and worthless.

The unanswered question here is, “Why do certain genes resemble one another in these two unrelated taxa?” Now there’s another subject for a PhD thesis.

Figure 2. Flamingo and grebe illustration from Nat Geo article on birds.

Figure 1. Flamingo and grebe illustration from Nat Geo article on birds.

Earlier we looked at grebes and flamingoes
here in 2017. Apparently there has been no enlightenment among paleontologists since then. Where is the critical thinking?

Continuing from the Kuhl et al. abstract:
“All non-passerine taxa were placed with robust statistical support including the long-time enigmatic hoatzin (Opisthocomiformes), which was found being the sister taxon of the Caprimulgiformes.” [= nightjars, sailors [= barn swallows?], hummingbirds, unrelated taxa in the LRT]

In the LRT the hoatzin nests between sparrows and parrots because they look alike, both overall, and in detail, location and diet. Relatives

If you have not learned this already,
genomic studies over deep time lead one to madness.

From the press release:
“For the first time, they have been able to clarify the relationship of all families of non-passerine birds and almost all families of passerine birds.  The new family tree is based on gene sections that do not code for proteins, but contain sequences that are specific to the families and their genera.”

Better to stick with a phenomic study that makes sense, like the LRT. Chickens and ducks are not related in the LRT.  That makes sense because they don’t resemble each other. Parrots and hawks are not related in the LRT. That also makes sense, but genomic studies put each of these two pairs of taxa together.

As mentioned above, we looked at Prum et al 2015
earlier in a three-part series ending here demonstrating several times that genomic studies do not replicate phenomic studies in the sort of deep time that brought us birds (Late Jurassic to the Present).

Genomic studies are EXCELLENT
over short phylogenetic time. For this reason genomic studies are used by the judicial system. For this reason paleontologists think genomic studies should supersede phenomic  studies. However, tests document the fact that genomic studies produce mismatches (taxa that do not look alike, Fig. 1) over deep time. Paleontologists realize this, but continue to put their faith in genomic studies, hoping that someday the last common ancestor of flamingoes (genus: Phoenicopterus) and grebes (genus: Aechmophorus) will someday be discovered in the fossil record.

The LRT has already recovered that last common ancestor,
a taxon close to the late-surviving, but extant megapodes, Megapodius and Early Cretaceous Juehuaornis. You’ll notice (Fig. 1) that clade includes nearly all crown birds.

Figure 3. Subset of the LRT focusing on birds. Note the separation of the duck clade from the chicken clade.

Figure 1. Subset of the LRT focusing on birds. Note the separation of the duck clade from the chicken clade.

The hallmarks of the Scientific Method include:

  1. asking a specific question
  2. devising a hypothesis
  3. experimenting to gather data
  4. analyzing the data, and then
  5. evaluating whether the hypothesis is correct based on the experimental data.

When the data support the hypothesis, the findings can be published or shared.
What happens if the findings do not confirm the hypothesis? Answers here.

Kuhl et al. 2020 was a complete waste of time for the nine co-authors, the editors, referees and innumerable readers who all believed the flawed premise of this genomic hypothesis of interrelations. Where is the genomic study that replicates phenomic studies like the LRT? When that happens, we’ll have that long sought validation.

Pertinent Carl Sagan – ‘A way of thinking’ YouTube video.

Kuhl H, et al. (8 co-authors) 2020. An unbiased molecular approach using 3″UTRs resolves the avian family-level tree of life. Molecular Biology and Evolution, msaa191 (advance online publication) doi: https://doi.org/10.1093/molbev/msaa191


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