Natalie Angier

Evidence now suggests, for example, that girls may not be born with all the eggs they’ll ever have in life—long a bedrock principle of reproductive biology—but instead retain the power to generate new eggs well into their postfetal years.

When I wrote Woman, the use of formulations like Prempro—a combination of estrogen and synthetic progesterone—was on the ascent, prescribed to millions of women aged fifty and older whose own ovaries had retired from the hormonal supply business

Chapter 12 remain relevant. Is menopause an adaptation, shaped by the forces of natural selection, or a byproduct of an unnaturally extended lifespan

Menstrual cycle is an alarming clock that cannot be stopped until nature wills it. Moon, month, menses: same word, same world

The image of the nested Russian dolls is used too often. I see it everywhere, particularly in descriptions of scientific mysteries (you open one mystery, you encounter another). But if there were ever an appropriate time to dust off the simile, it’s here, to describe the nested nature of the matriline. Consider, if you will, the ovoid shape of the doll and the compelling unpredictability and fluidity of dynasty. Open the ovoid mother and find the ovoid girl; open the child and the next egg grins up its invitation to crack it. You can never tell a priori how many iterations await you; you hope they continue forever. My daughter, my matryoshka

Yet by menopause, few if any eggs remain in the ovaries. The rest have vanished. The body has reclaimed them

that point a doctor may recommend donor eggs, combining the seeds of a younger woman with the sperm of the older woman’s husband (or lover or male donor) and then implanting the resulting embryo in said senior’s uterus. Using donor eggs can make a woman of forty act like a twenty-five-year-old, reproductively speaking. Who knows why? But it works, oh girl does it work, so well that suddenly you’re no longer in the teens of probability but instead have about a 40 percent chance of giving birth in a single cycle of in vitro maneuvers. That

Male twins share the totality of their maternal X chromosomes, as well as having all the other chromosomes in common, but female twins have a diverging patchwork of maternal and paternal X chromosomes operating in different parts of their bodies.)

Could brain mosaicism also explain why multiple personality disorder (assuming we give it the benefit of the doubt as a genuine psychiatric disorder) so often seems to strike women? Could sufferers indeed be afflicted with internal clashing commandos, mother-speak and father-speak, cacophonous enough to spin off other fragmentary characters? As Teresa Binstock, of the University of Colorado, pointed out to me, nobody can answer such questions yet, because the idea of brain mosaicism is so new “that most neurologists, neuroanatomists, and cognitive neuropsychologists have not yet thought about it.”

was told at the same time that I’d have to commence hormone replacement therapy, take estrogen. I was told that I would never have menstrual cycles, that I would never have children.”