Categorical edge-based analyses of phylogenomic data reveal conflicting signals for difficult relationships in the avian tree (5 scientists writing in the preprint server bioRxiv). The authors include noted evolutionists Joel Cracraft and Steven A. Smith. Here is a digest of admissions in the Abstract:
- Phylogenetic studies of genetic evidence often fail to match a Darwinian tree pattern.
- Failures occur even in with whole-genome studies. In such cases, they can’t blame a lack of data.
- The more they look at “contentious” points in the tree, the more the problems mount.
- They can’t blame noise in the data. Even if there is noise, some of the mismatches reflect true biological facts.
- The five authors examined molecular evidence for bird species, and could not resolve the conflicts.
- Even when they removed the most problematic mismatches, conflicts remained.
- They got different matches for bird groups depending on which genes they looked at.
- How can the Hoatzin, a puzzling tree bird with claws on its wings, be closest to shorebirds?
- Mismatches in bird phylogeny “may be even greater than appreciated based on previous studies.”
A mutation-selection model of protein evolution under persistent positive selection (Tamuri and dos Reis in bioRxiv). This preprint reveals that the measure of “positive selection” is flawed. They looked for persistent positive selection in their study of “protein evolution” by mutation and natural selection. They say the ratio dN/dS (non-symmetrical vs symmetrical substitutions, abbreviated ω) is “arbitrary” because “in real proteins many mutations are highly deleterious and are removed by selection even at positively-selected sites.” And yet ω is the measure that is highly used in studies of “positive selection” (the only kind of natural selection that matters, because it would signal progress).
Fossil Conflicts
Fossil apes and human evolution (Almécija and 5 others, Science 7 May 2021, Vol. 372, Issue 6542, eabb4363,
DOI: 10.1126/science.abb4363). The fossils we have of apes and humans do
not lead to a consistent story of evolution. Though evolutionists
themselves, these authors from Spain and from the American Museum of
Natural History (AMNH) deny that the evidence supports the chimpanzee as
the closest human relative among the apes.
Ever since the writings of Darwin and Huxley, humans’ place in nature relative to apes (nonhuman hominoids) and the geographic origins of the human lineage (hominins) have been heavily debated. … “Top-down” approaches have relied on living apes (especially chimpanzees) to reconstruct hominin origins. However, “bottom-up” perspectives from the fossil record suggest that modern hominoids represent a decimated and biased sample of a larger ancient radiation and present alternative possibilities for the morphology and geography of the Pan-Homo LCA. Reconciling these two views remains at the core of the human origins problem.
The following sentence sums up the problem with human evolution studies: “Overall, the researchers found that most stories of human origins are not compatible with the fossils that we have today.”
As so often occurs when Darwinians fess up to problems in the data, they hope the solution will come in futureware.
One more slam from the authors at their colleagues is found in the “Outlook” section of the paper: “It
is also imperative to stop assigning a starring role to each new fossil
discovery to fit evolutionary scenarios that are not based on testable
hypotheses.” CEH