When I Was Young

MANCHESTER

SCIENTISTS agree that dinosaurs are the ancestors of today’s birds. But just why did some of them sprout wings?

Until now, the answers offered have often referred to a better chance of escaping predators.

But researchers at the University of Manchester have advanced a more subversively romantic notion: They suggested that sexual selection – which gives animals an advantage in choosing a mate – may have been the key factor, reported The Daily Telegraph.

In the evolutionary process known as sexual selection, traits viewed as more attractive by the opposite sex become both more common and more pronounced, since mating animals gravitate towards them.

“One theory is that these feathered dinosaurs used their forelimbs in some sort of sexual display, so maybe they ran around with their arms outstretched to show off how pretty their feathers were,” Dr Robert Nudds, a biologist at the University of Manchester, was quoted as saying.

He bolstered the idea with research showing that the notion “learning to fly”, which supposedly helped give the creatures an advantage against predators – by giving them extra thrust to climb away from trouble – was false.

Primitive wings, the Manchester research suggested, actually reduced the ability of animals to run fast and were, therefore, inefficient.

“Two-legged animals use their forelimbs in asymmetrical movements to help counteract the force from the legs and to stop their body from rotating as they run. If an animal started running with its limbs held out to the side, then it would be at a disadvantage,” Dr Nudds told The Daily Telegraph.

He then theorised that there must have been another reason why wings were evolutionally favoured. He said: “Something other than simple natural selection drove the evolution of symmetrical forelimb posture.”

The answer: It was sexy.

Dr Paul Barrett, a palaeontologist at London’s Natural History Museum, observed that the truth may be in a mix of factors.

The first birds emerged 145 million years ago.


From myPaper, My News, World
Tuesday, 07-April-2009