Tuesday, 13 October 2015

No Doubt Now, Birds Evolved From Dinosaurs

A comprehensive phylogeny of birds (Aves) using targeted next-generation DNA sequencing | Nature.

Just a couple of days ago I wrote about another one of those 'transitional' fossils creatonists insist aren't there, and how this one shows how birds had evolved out of theropod dinosaurs and should more properly be regarded as flying dinosaurs.

I also speculated about whether it was warm-bloodedness and feathers which helps them survive the climate change following the the meteor strike which probably abruptly exterminated the terrestrial dinosaurs so opening up niches for the birds and mammals to radiate into.

This is no great shakes of course; it's what anyone who knows anything about the subject would have known or could easily have deduced, but, as though to confirm it, we have this paper published today in Nature.

A team of evolutionary biologists in conjunction with Yale University have resolved the avian family tree and shown that they did indeed evolve out of the theropod group of dinosaurs and radiated rapidly about 65 million years ago with some 10,000 species differentiating in just a few million years. The debate now isn't about whether birds are modern dinosaurs but about the details of how they evolved over the last 65 million years to be as they are today.

Although reconstruction of the phylogeny of living birds has progressed tremendously in the last decade, the evolutionary history of Neoaves—a clade that encompasses nearly all living bird species—remains the greatest unresolved challenge in dinosaur systematics. Here we investigate avian phylogeny with an unprecedented scale of data: >390,000 bases of genomic sequence data from each of 198 species of living birds, representing all major avian lineages, and two crocodilian outgroups. Sequence data were collected using anchored hybrid enrichment, yielding 259 nuclear loci with an average length of 1,523 bases for a total data set of over 7.8 × 107 bases. Bayesian and maximum likelihood analyses yielded highly supported and nearly identical phylogenetic trees for all major avian lineages. Five major clades form successive sister groups to the rest of Neoaves: (1) a clade including nightjars, other caprimulgiforms, swifts, and hummingbirds; (2) a clade uniting cuckoos, bustards, and turacos with pigeons, mesites, and sandgrouse; (3) cranes and their relatives; (4) a comprehensive waterbird clade, including all diving, wading, and shorebirds; and (5) a comprehensive landbird clade with the enigmatic hoatzin (Opisthocomus hoazin) as the sister group to the rest. Neither of the two main, recently proposed Neoavian clades—Columbea and Passerea1—were supported as monophyletic. The results of our divergence time analyses are congruent with the palaeontological record, supporting a major radiation of crown birds in the wake of the Cretaceous–Palaeogene (K–Pg) mass extinction.*

A comprehensive phylogeny of birds (Aves) using targeted next-generation DNA sequencing
Richard O. Prum, Jacob S. Berv, Alex Dornburg, Daniel J. Field, Jeffrey P. Townsend, Emily Moriarty Lemmon & Alan R. Lemmon
Nature (2015) doi:10.1038/nature15697

*Copyright © 2015, Rights Managed by Nature Publishing Group. Reprinted under licence No. 3727221250801

Each major niche such as water quickly gave rise to a whole range of new species. For example, all the diving, wading and shore birds such as penguins, gulls and pelicans belong to the same major group. Once a group had diversified into its major niche, it seems to have been rare for them to switch to another major niche. There are no diving raptors or night-flying finches, for example.

These birds just diversified rapidly after dinosaurs went extinct. Now that these relationships have been identified, we can more accurately study how color vision, feather structure and many other bird traits have evolved through time.

Emily Moriarty Lemmon,
Department of Biological Science,
Florida State University.
Some results were perhaps a little surprising. Nightjars, for example, are in the same group as swifts and hummingbirds (the latter two being in the same group has been known about for some time) and falcons are in the same major group as parrots.

And of course, it almost goes without saying, the findings are entirely consistent with the palaeontological record and the neo-Darwinian Theory of Genetic Evolution, and entirely inconsistent with special creation just a few thousand years ago.

Surely it's time now that creationists stopped their idiotic denial of this sort of evidence and accepted that their childish fairytale is just that. Every piece of research into the origins and relationships of different species, no matter whether it looks at fossils, anatomy, genetics, proteins or metabolic pathways is always entirely consistent with the scientifically accepted model of evolution on a very old Earth.

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