British scientists managed to establish that first appeared on Earth after all the chicken and then the egg.
The well-known dilemma was solved thank to the study of substance ovocleidin — a special type of protein. Ovocleidin forms the egg shell and the substance can only produced in the body laying hens. The process begins and ends in the ovaries of adult chicken, scientists say.
Otmechaetsya that this protein helps to form the shell eggs from other birds.
Previously scientists who conducted other studies, argued that the Earth first came the egg. Arguing that einclude existed before birds.