Why Ostriches Can't Fly
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- DeliaTheArtist
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more from Green:
http://www.livescience.com/animals/flightless-birds-100128.html
"As the Age of Dinosaurs came to an end, some flying birds swooped in and took up the newly available niches, foraging on the ground, growing larger over the generations, and eventually losing the ability to fly. So suggests new research into the DNA of the birds.Scientists had long thought the world's largest flightless birds, the ratites — which include African ostriches, Australasian emus, kiwis and cassowaries, South American rheas and the extinct New Zealand moas — shared a common flightless ancestor.
"Ratite birds have been thought of as relics of the former Gondwanan supercontinent, which combined Africa, South America, Australia, Antarctica, New Zealand, India and Madagascar," Phillips said.
However, it was then a puzzle as to how these flightless birds dispersed over the seas after Gondwana had largely broken up roughly 110 million years ago.
Genetic analysis in 2008 suggested that all these flightless birds actually shared a common flying ancestor. And new genetic research confirms that view and suggests a reason why the birds became grounded independently after dispersing geographically.
"Various ideas about hopping between temporary islands and now-sunken micro-continents are no longer necessary — the ancestors of all these birds could simply have flown," said researcher Matthew Phillips, an evolutionary biologist at the Australian National University in Canberra."
http://www.livescience.com/animals/flightless-birds-100128.html
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- groups:
- Green, Science, Science & Nature, History
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- tags:
- Evolution
