Which came first, the chicken...

...or the egg? Eric Schwitzgebel thinks he has the answer (my emphasis):

If we accept the theory of evolution, as I think we should, then the chicken derives from a lineage that ultimately traces back to non-chickens. (The issues here are the same whether we consider the domestic chicken to be its own species or whether we lump it together with the rest of gallus gallus including the Red Junglefowl from which the domestic chicken appears to be mostly descended.) The first chicken arose either as a hybrid of two non-chickens or via mutation from a non-chicken.
___

From a genetic perspective, since the chicken and egg share DNA, they form a single Sorites unit. Within this unit, the egg clearly comes first, since the chicken is born from the egg, sharing its DNA, and there is a DNA difference between the egg and the hen from which that egg is laid.