By Rebecca Morelle
Science reporter, BBC News
Scientists believe they could be a step closer to solving the mystery of how the first birds took to the air.
A study published in the journal Nature suggests that the key to understanding the evolution of bird flight is the angle at which a bird flaps its wings.
The US team found that birds move their wings at the same narrow angle, whether they run, fly or glide.
They conclude that early birds may have begun to fly by simply learning to flutter their wings at the right angle.
The research was carried out by scientists at the Flight Laboratory at the University of Montana.
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more:
http://news.bbc.co.uk/2/hi/science/nature/7205086.stm