It's a question that has stirred pub debates through the ages: What came first, the chicken or the egg? Now a philosopher, backed up by a geneticist and a chicken farmer, claims to have found the answer. It was the egg.
Put simply, the reason is down to the fact that genetic material does not change during an animal's life. Therefore the first bird that evolved into what we would call a chicken, probably in prehistoric times, must have first existed as an embryo inside an egg.
Professor John Brookfield, a specialist in evolutionary genetics at the University of Nottingham, said the pecking order was clear. The living organism inside the eggshell would have had the same DNA as the chicken it turned into.
"Therefore, the first living thing which we could say unequivocally was a member of the species would be this first egg," he said. "So, I would conclude that the egg came first."
The same conclusion was reached by Professor David Papineau, of King's College London, and Charles Bourns, a poultry farmer and the chairman of a trade body called Great British Chicken. Professor Papineau, whose subject is the philosophy of science, agreed that the first chicken came from an egg and that proves there were chicken eggs before chickens.
He said people were mistaken if they argued that the mutant egg belonged to the "non-chicken" parents.
"I would argue that it is a chicken egg if it has a chicken in it," he said. "If a kangaroo laid an egg from which an ostrich hatched, that would surely be an ostrich egg, not a kangaroo egg."
Mr Bournswas also in the pro-egg camp. "Eggs were around long before the first chicken arrived," he said.