Aristotle’s hypothesis may have been flawed, but it is not surprising that he did not consider a more accurate version of the inner workings of the female form – one was not available. Though Aristotle discussed the uterus in his book, very little had been revealed about the female reproductive organs at the time he wrote On the Generation of Animals.
The ovaries, referred to as ‘female testicles’, probably were discovered by an anatomist, Herophilos, who performed both animal and human dissections, some of them for public viewing, from his base in Alexandria, Egypt. But Herophilos was reportedly born in 335 BCE, just thirteen years before Aristotle’s death. Soranus, a physician from an area of what is now Turkey, appears to have dissected human subjects as part of his investigation into obstetrics and women’s diseases. He displayed a clear understanding of the various sections of the uterus, placenta, bladder, and vagina, which he described in great anatomical detail. Soranus’s dissections, however, were conducted in the second century BCE – also well after Aristotle’s time. For more than a millennium afterwards, little advance was made in understanding the true nature and function of these mysterious female parts, because in large part, human dissections were widely proscribed, which meant that cadavers were not openly available for this sort of poking and probing. Instead, physicians had to rely on the writings of Aelius Galen, the second-century Greek surgeon considered to be the most influential medical writer in all history.
Galen was born in Pergamon, the great cultural centre of Asia Minor under Roman rule. He came from a family of wealth and education, and he followed suit, training in philosophy, mathematics, and natural sciences. He had probably been influenced by his father in his choice of a career in medicine. The story goes that the Greek god of healing, Asclepius himself, appeared to Galen’s father in a dream to offer vocational guidance intended for his son. After this god-given training as a physician, Galen visited Alexandria, where the doctors placed great emphasis on the study of anatomy. On his return home, he was appointed physician to the gladiatorial games. This gave him the dubious privilege of regularly confronting the horrendous injuries inflicted in the arena. As ghastly as the job may have been, operating on the wounds allowed him to gain first-hand experience of human anatomy. He supplemented his observations of battered gladiators with dissections of abandoned corpses.
Galen lived some five hundred years after Aristotle, and medical knowledge had evolved. So he decided to develop his own theory of sex differences, based on his own work. In contrast to Aristotle’s belief that the sperm was simply the seed that laid out the final form of the foetus, Galen thought the foetus’s development was not just influenced but powered by the sperm, and that the female was actually a male in reverse. He was notably inspired by Herophilos, whose teachings were still popular in Alexandria and from whom he adopted the idea that a woman’s ovaries were essentially testes. But Galen went further, positing that the female genitalia are identical to those of the male, only turned inward. According to this ‘reversal’ theory, the uterus was an inverted scrotum. This of course did not explain the function of those female parts that males lack – for example, more developed breasts. And the uterus did not serve the same purpose as the scrotum, a fact of biology that would have been understood even in Galen’s day. But Galen was silent on these reproductive discrepancies.
When compared with modern views of reproductive evolution, though, Galen’s reversal theory does not seem to have got everything wrong. For instance, in his essay ‘Male Nipples and Clitoral Ripples’, the renowned evolutionary biologist Stephen Jay Gould argued that the man’s body is not a basic structure from which a woman’s diverged:
Males and females are not separate entities, shaped independently by natural selection. Both sexes are variants upon a single ground plan… Male mammals have nipples because females need them – and the embryonic pathway to their development builds precursors in all mammalian foetuses, enlarging the breasts later in females but leaving them small (and without evident function) in males.
Likewise, Gould imagined that the clitoris and the penis were ‘one and the same organ’, their size determined by the relative balance of hormones, particularly testosterone, during foetal development. The same could be said of women’s labia majora and men’s scrotal sacs, though with these organs the presence of testosterone triggered a folding and fusing of the skin in the males. Gould took his argument a further step into controversy by stating that the clitoris was something like the appendix, an evolutionary artefact that no longer served a purpose. But on a more basic level, he supposed ‘the external differences between male and female develop gradually’, so much so that, ‘from an early embryo so generalized that its sex cannot be easily determined’.
Since the early 1950s, when DNA was discovered to be the elusive matter that allows us to inherit traits from our parents, an incredible amount of scientific progress has been made. The complete
