

It’s both. But speciation takes time even with punctuated equilibria… Actually finding the time when the egg yielded a chicken instead of a proto-chicken is not so likely to be fruitful. There were also other species that reproduced using eggs that existed before the chicken did… so we can say for sure that the egg came first as long as we allow for eggs from other species, although it doesn’t really seem in the spirit of things.
Yippee