Primeiro? Foi o ovo.

It's the conundrum that has puzzled mankind for generations: what came first, the chicken or the egg? Now, however, a geneticist, a philosopher and a farmer have finally solved the age-old question. Genetic material does not change during an animal's life, therefore the first bird that evolved, into what is now known as a chicken, must have first existed as an embryo inside an egg. The team concludes that it was, therefore, the egg that came first.