Friday, January 29, 2010

Birds became fat as dinosaurs died

A sedentary lifestyle is often liable for causing obesity among humans.

Actually, the same thing happened to certain birds 65 million years ago.
The vanishing of Dinosaurs from earth at that time made the flying ancestors of the emu, cassowary and the ostrich lazy, new Australian research has found.

Instead of soaring away from gigantic beasts, they fattened up and turn into flightless, the study by Canberra's Australian National University (ANU) found.
New Zealand's now extinct flightless moa birds descended from a small, South America flying fowl, the examination of mitochondrial genome series found.
Earlier, scientists believed flightless birds, also known as ratites, shared a common flightless ancestor.

Dr Matthew Phillips the Study director said that as dinosaurs died out, natural selection favored the fatter birds.

“The Extinction of the Dinosaurs likely lifted predation pressures that had previously chosen for flight and its necessary constraint, small size,” he said.
Lifting of this pressure and added abundant foraging opportunities would then have selected for larger size and consequent loss of flight.

Dr Phillips said-“The ancestors of flightless birds originally flew to other parts of the world from the northern continents.”

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