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Jan 27, 2015

New ideas about evolution of bird species

Wildlife has just published a story from Smithsonian Science which states that the genomes of modern birds reveal how they emerged and evolved after the mass extinction that wiped out the dinosaurs 66 million years ago.   The family tree of modern birds has long been the subject of of debate and the evolution of more than 10,000 species has not been known.   Now a four-year international collaboration of more than 200 scientists in 20 countries has sequenced, assembled and compared full genomes of 48 bird species.   The first findings suggest some remarkable new ideas about bird evolution.   The first paper published in Science presents a new family tree for birds, based on whole-genome data.   The whole-genome analysis dates the evolutionary expansion of 'Neoaves' to the the time of the mass extinction event 66 million years ago that killed off all dinosaurs except some birds.   This contradicts the hypothesis in earlier research that 'Neonaves' arose 10 to 80 million years earlier than that.   Using the new geonomic data, the conclusion is that only a few bird lineages survived the mass extinction.   These gave rise to the more than 10,000 'Neoaves' species that now comprise 95% of all the bird species we have today.   Researchers believe that the ecological niches left by the mass extinction event may have allowed birds' rapid species radiation, in less than 15 million years, which explains modern avian biodiversity.   Visit Science to learn more.
Comparing the artistic image at top of a prehistoric avian creature (which was probably flightless at this stage) to the Shoe-billed Stork, at right, a visual similarity emerges, much more so than a comparison with a tiny hummingbird would produce.   Interesting.

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Photo by David LI/

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