We’ve been wondering why
phenomic (trait-based) studies do not completely match genomic (molecule-based) studies in phylogenetic analyses with similar taxon lists.
the large reptile tree is a phenomic study of vertebrates that includes extinct and extant birds as a subset/clade. Prum et al. 2015 is a genomic study of extant birds. The bird parts of their topologies do not match.
Here is one answer @ 8:29 in.
“It quickly became clear that most traits in a human being aren’t caused by a single gene or a handful of genes. They often arise out of the complex interaction of hundreds or thousands or even tens of thousands of genes and other bits of DNA working in concert.”
“So the challenge sort of shifted. It wasn’t about finding a single gene or mutation for any one thing. It was about mapping these huge swaths of the genome and looking for variations.”
For example, they found,
“20,000 spots in the genome affect height.”
only phenomic studies can include a wide gamut of fossil taxa.
only phenomic studies let you see and document the gradual accumulation of traits in all sister taxa, echoing actual events in the family tree of vertebrates.
Bonus YouTube video!
Here is a demonstration
for the use of wings/winglets before flight was possible in both pre-pterosaurs and pre-birds. Originally I was thinking only of using wings to impress potential mates. Here defending eggs or young from intruders is also a possibility. While these bird parents are keeping their wings outstretched and relatively still, flapping them vigorously and coming down on the lizard’s back would only add to the lizard’s dilemma.
Prum et al. 2015