At Genomicron, T. Ryan Gregory presents evidence from a colleague's recently published paper and his own grad students' work to show that pterosaur genomes were downsized prior to evolving the ability to fly. Pterosaurs could fly 70 million years before birds and 150 million years prior to bats. "The story thus seems to be that genome reduction occurred in the dinosaur lineage of which birds are descendants before flight (so did feathers, bipedalism, and other characteristics), but were later further adjusted when flight arose (as were feathers, etc.)," he writes. "So it's not flight per se that matters, but a feature linked with flight."
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