Fish could explain how we developed arms, legs

London, Aug 8 (IANS) The American paddlefish, one of the oldest fish on the planet, could explain why we developed our arms and legs, according to scientists.

Researchers have found that the fish duplicated its entire genome about 42 million years ago.

To study how human limbs develop, scientists compared the limb-building genes found in mice with fin-building genes in fishes, the Daily Mail reported Wednesday.

Previous research on paddlefish suggested that fishes possessed the genetic toolkit required to grow limbs long before the evolution of the four-limbed creatures (tetrapods) that developed into reptiles, birds, amphibians and mammals.

"We found that paddlefish have had their own genome duplication," said Karen Crow, assistant professor of biology at San Francisco State University.

"This creates extra genetic material that adds complexity to comparative studies. It may change the way we interpret studies on limb development."