Empedocles says that the greater part of the members of animals were
generated by chance...
What, then, hinders but that the parts in Nature may also thus arise
[from necessity]? For instance, that the teeth should arise from
necessity, the front teeth sharp and adapted to divide the food, the
molars broad and adapted to breaking the food into pieces. It may
be said that they were not made for this purpose, but that this purposive
arrangement came about by chance; and the same reasoning is applied
to other parts of the body in which subsistence for some purpose is
apparent. And it is argued that where all things happened as if they
were made for some purpose, being aptly united by chance, these were
preserved, but such as were not aptly made, these were lost and still
perish, according to what Empedocles says concerning the bull species
with human heads. This, therefore, and similar reasoning, may lead
some to doubt on this subject.
-- Aristotle, Physics, Fourth Century B.C.
