Chickens: what came first? Scientists crack genetic code

Scientists say they have unravelled the genetic code of the chicken, an evolutionary trek that began before the age of the dinosaurs and led to the emergence of the world's most important bird today.

Scientists say they have unravelled the genetic code of the chicken, an evolutionary trek that began before the age of the dinosaurs and led to the emergence of the world's most important bird today.

HT Image

The secrets of the chicken genome could lead to super-hens -- new breeds which will lay more eggs, have more meat and be more resistant to disease than any poultry that has walked the Earth.

And there could be health benefits too, by helping the fight against bird flu, a disease that could threaten millions of people, they hope.

An international consortium took a DNA sample from the red jungle fowl (Latin name Gallus gallus), which is believed to be the wild ancestor of domestic chickens, and decrypted its code.

The draft, which appears in this week's issue of the British journal Nature, comprises about a billion base pairs, the "rungs" which make the ladder in the double helix of DNA.

Gallus gallus -- the first bird to have its DNA code sequenced -- has an estimated 20,000-23,000 genes, which puts the total in the same ballpark as that for Man, the authors say. "About 60 percent of the chicken protein-coding genes have human equivalents," says one of the researchers, Peer Bork of Germany.

Indeed, a closer scrutiny shows that humans and chickens -- indeed, all vertebrates -- shared a common ancestor around 310 million years ago, even before the dinosaurs emerged, they say.