From YahooNews:

Philosopher, scientist, farmer crack chicken-egg question

LONDON (AFP) - Which came first, the chicken or the egg? According to a scientist, a philosopher and a chicken farmer, it was the egg, British newspapers reported.

The key to the age-old question apparently lies in the fact that since genetic material does not change throughout an animal’s life, the first bird that evolved into a chicken must have initially existed as an embryo inside an egg.

Professor John Brookfield, from England’s University of Nottingham, concluded that because of this, the living organism inside the eggshell would have had the same DNA as the chicken it turned into.

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