What is it for an animal to be female, or male? An emerging consensus among
philosophers of biology is that sex is grounded in some manner or another on an
-
isogamy, that is, the ability to produce either large gametes (egg) or small gametes
(sperm), though the exact nature of this grounding remains contentious. Here we
argue for a new conception of this relation. In our view, one’s sex doesn’t depend
on the kind of gamete one is
capable
of making, but on the kind of gamete one is
designed
to make, where design is understood in terms of an evolutionary or on
-
togenetic selection process. Specifically, we argue that what it is to be, say, male,
is to have a part or process that has the (proximal or distal) biological function of
producing sperm. We outline and defend our view, and sketch some implications
for scientific and social problems related to sex.