In terms of evolution, the egg came first, produced by the most recent immediate ancestor of the chicken that was itself not a chicken. Now, DNA analysis of bones of chickens that lived a mere 200 to 2300 years ago in Europe, shows that domestic chickens, Gallus gallus domesticus, may have looked very different from the barnyard roosters and hens we see on farms around the world today. The results suggest that some of the traits we associate with modern domestic chickens - including their yellowish skin - only became widespread in the last 500 years, much more recently than previously thought. It's a blink of an eye from an evolutionary perspective, explains Greger Larson of Durham University, UK. The study is part of a larger field of research that aims to understand when, where and how humans turned wild plants and animals into the crops, pets and livestock we now know.
A chicken and egg situation