Actually, scientists have answered the question of which came first. Because living things evolve through changes in their DNA, and because in each animal the DNA is the same in every single cell...

Actually, scientists have answered the question of which came first. Because living things evolve through changes in their DNA, and because in each animal the DNA is the same in every single cell (beginning with the first cell in reproduction, the zygote), then chickens evolved from nonchickens through a series of tiny changes caused by mutations in the male and female DNA in the process of reproduction. Such changes would only have an effect when a new zygote was created. So, what happened was that two nonchickens mated, but the zygote contained the mutations that produced the first “chicken.” When it broke through its shell—presto, the first chicken. So the egg came first.