Originally Posted by D

From the philosophical point of view... Aristotle, in his Metaphysics, said "Actuality must proceed potentiality"... since a chicken represents an actual being, and an egg could be said to represent a potential being, the chicken must have come first.

That said, from a biological standpoint, there must have been some sort of proto-chicken species that existed before the modern "chicken," and these proto-chickens, no doubt, laid eggs of their own... and probably laid the first "mutant" that would later be called a "chicken" in an egg... so, in that respect, perhaps the egg came first.

But, then there's also the idea that the egg containing the first chicken was actually not a "chicken" egg, but a proto-chicken egg, which just happened to contain a mutant proto-chicken that would eventually go on and be successful enough to help spawn its own species...

Then, it's almost an argument of semantics... for the proto-chicken egg is still an "egg," even if not a "chicken egg"....

So it goes back to the original question, and how you'd define "egg." If you're to define it as "any egg," well - of course the egg came first, because there were plenty of species laying eggs before the first _birds_ came into existence... hell, even before anything was walking on the earth, fish were laying plenty of eggs...

But, if you're defining it in a more narrow sense... as a "chicken egg," then it could be said that the chicken came first, for the egg that the first unhatched chicken would be all nestled up inside of would actually be a proto-chicken's egg, that happened to contain the mutant proto-chicken chicken... and the first "chicken egg" wouldn't have said to be first existed until that mutant chicken matured and laid its own egg....

Which backs up Aristotle's assertion that actuality comes first.

Unless you define an egg as "an egg with a chicken inside of it"... and, in that case, Biology and Aristotle's Metaphysics might be considered to not see eye to eye.