Friday, January 11, 2013 1:00:16 PM
Actually at about 6 weeks in development the embryo forms both mesonephric ducts (which will form the epididymis in males) and paramesonephric ducts (uterine tube in females) and one will degenerate depending on hormones (due to the Sex determining Region of the Y chromosome[SRY]), which is why if there is no Y gene or it is inactive the default gender is female. At this time the external genitals are identical in both males and females and are not fully differentiated (macroscopically) until week 20. Lifted straight from an anatomy textbook, almost verbatim. Your not gender neutral or female at that point, your both immature genders.
Thursday, January 10, 2013 7:13:29 PM
Around 1:18, he mentions "If the Y chromosome does not become activated..." That's how you can get XY females, like the late movie star Kim Novak. Infertile, but often very feminine. Makes you think.