Chickens – Not just a good source of protein…
After four years of research undertaken by over 400 scientists in 200 countries, it has been revealed that all birds evolved from a group of feathered Dinosaurs. When, about 65 million years ago, the larger dinosaurs were wiped out, a few feathered creatures survived and thrived. Their evolution, thought to have been fairly rapid, produced egg laying, feathered critters that walked on two legs.
The study, which involved comparing DNA samples ranging from birds such as the crow, duck and pigeon, to the eagle, ostrich and woodpecker, it was discovered that the domestic chicken has the closest chromosome pattern to those primitive creatures, making it the nearest thing that we have to a dinosaur today.
“Ever since the discovery of the fossil bird Archaeopteryx in 1861, it has been clear that living birds are descended from toothed ancestors. However, the history of tooth-loss in the ancestry of modern birds has remained elusive for more than 150 years,” said Mark Springer of the University of California.
Comparing the genomes of birds to other animals revealed that whilst the emergence of feathers initially must have been purely for warmth, more colorful plumage led to mating success. Researchers found that agricultural and domestic birds have 8 times the genes linked to feather coloration than waterbirds.
Remarkably, it was found that a group of 50 genes that give birds the ability to sing, are very similar to the genes of the human voice.
“This means that vocal learning birds and humans are more similar to each other for these genes in song and speech areas in the brain than other birds and primates are to them,” said Erich Jarvis at Duke University in North Carolina.
The avian family tree project has given a huge insight into how penguins survive such harsh Antarctic conditions. Researchers led by Cai Li, at the Beijing Genomics Institute, studied the genomes of Adélie and Emperor Penguins and found many genetic changes that help them adapt to the frigid conditions. Both penguins were found to have a group of souped up gene sets which produce the protein for those dense, short feathers which keep the cold out and the heat in.
Loosing their ability to fly gave penguins the ability to uses their wings underwater. Writing in the journal GigaScience, Li’s team explains that mutations in one of the genes that re-shaped penguins wings can also be found in the genes of Ellis-van Creveld syndrome, a genetic disorder which causes short ribs and short limb dwarfism in people.
So show some respect for that humble chicken next time you serve it up. It has come a long way!