Surely sex is determined at conception by the chromosomes in the sperm?
In most cases that is reasonably correct, but there are a number of conditions in which chromosomal sex is a completely unreliable over-simplification. Compare this with the statement that the human eye has a lens which can focus on near or far objects. This is true for the average person but not for the millions of people who have imperfect eyesight. There are many women who have never been transsexual but who have so-called “male” chromosomes and many men, never transsexual, who have so-called “female” chromosomes. There are never-ts women who were born with bits of male genitalia and never-ts men who were born with ovaries. There is no guarantee that when nature makes something so complex as a human body it will always make them exactly conform to fixed stereotypes. Stereotypes are made by mortals, not nature. Further, environmental pollution is changing the supposed straightforwardness of the business of sexual identity and chromosomes. Fish and other animals are now being found to
