To take Brewster’s question seriously, there actually is a biological answer. At one point in the evolution of the class aves that was a “proto-chicken” (i.e.: a bird almost, but not quite, like a modern chicken.) That avian female mated with another “proto-chicken” of her species and generated an egg (or probably a number of them.) That egg contained an embryo that had the genetic mutation which resulted in the first modern chicken. That first modern chicken (and presumably its other siblings) had enough of an evolutional edge to eventually become dominant. . Thus, it is the egg which came first.
To take Brewster’s question seriously, there actually is a biological answer. At one point in the evolution of the class aves that was a “proto-chicken” (i.e.: a bird almost, but not quite, like a modern chicken.) That avian female mated with another “proto-chicken” of her species and generated an egg (or probably a number of them.) That egg contained an embryo that had the genetic mutation which resulted in the first modern chicken. That first modern chicken (and presumably its other siblings) had enough of an evolutional edge to eventually become dominant. . Thus, it is the egg which came first.