Women After All: Sex, Evolution, and the End of Male Supremacy Read Online Free PDF

alone, but the Y chromosome plays the key sex-determining role; however, that doesn’t make the Y itself a masterpiece. It’s a fraction of the size of the X and looks like a stunted sibling; this is not true in all sexual animals, but it is true in mammals. The Y, petite as it is, ordinarily carries one gene that tips the balance: this gene makes the testis determining factor, or TDF, which triggers the growth of testes from organs that would otherwise become (basically) ovaries. The testes take over from there by brewing specifically male hormones—androgens—that mold the rest of maleness. Another Y gene creates a molecule that suppresses female organs.
    Other genes on the X and other chromosomes make their mark on sexual development, but the TDF manufactured by the Y is the chemical key that unlocks the androgens. As we saw at the outset, we can think of maleness as a syndrome, a chromosomal defect shared by 49 percent of humans. It does serious damage. It quashes the body’s ability to create new life, causes excess death at all ages, shortens life, increases the risk of diseases ranging from heart attack to autism, and causes physical violence, among other symptoms. Most of this is due to androgen toxicity, mainly testosterone poisoning, although estrogen deprivation and other hormonal glitches play a role. But most of it can be traced back to the Y.
    Why “toxicity” and “glitches”? Isn’t this just rhetoric? No. The mammalian body plan is basically female. If you have just one X (Turner syndrome), you will not be fertile, but you will otherwise be female, as long as you have no Y. If you have two or more X’s but also a Y (Klinefelter syndrome), you will not be completely typical,but you will be basically male. There are rare cases of infertility in women who are found to be XY but are insensitive to androgens due to another gene. And a few men seem to be XX under the microscope but are found to have the key Y genes accidentally attached to one of their X’s—something that can happen in a slightly awry cell division. Otherwise it’s fair to say: the body plan is female unless the Y flips it into maleness.
    With this foundation, we can look at Barbin’s modern counterparts, and they will tell us much about the biological part of the male-female story. I will try to give them gender-neutral nicknames to avoid either backing them into a gender role or pinning them like scientific specimens.
    First, we have people born with ambiguous genitals who were XX embryos partly androgenized in the womb. This can happen either because of a naturally occurring condition or because their mothers were given a drug that mimicked androgens. One natural problem is congenital adrenal hyperplasia, and babies born with it—I’ll call them “Ahs”—have a genetically altered enzyme in the adrenal gland, so instead of just making its usual hormones (relating to stress and salt), the gland makes excess androgens. Ahs are born with their genitals somewhat masculinized, as well as with significant medical problems that can be treated but not cured. Some other XX babies with ambiguous genitals were exposed to medications related to progesterone. Unfortunately, progesterone has some of the same effects as androgens, a fact not known when the hormone was given to some women to help them keep their pregnancies. The resulting babies—I’ll call them “Andras”—also may have partly masculinized genitals but do not have medical problems.
    Ahs and Andras are two of the groups that make the “It’s a girl!” or “It’s a boy!” decree difficult. But often, like Barbin, they’ve been raised as girls. Some had their small penises removed sometime after birth so that as children they would have fairly typical-lookingfemale bodies. The Ahs also received hormones, plus further ones at puberty, in an attempt to fine-tune their adrenals and prevent masculine development. As for their genitals, psychologists until recently