It is actually correct.
In fact even testosterone evolved from estrogen.
"p. 988 "Human chorionic gonadotropin also exerts an interstitial
cell-stimulating effect on the testes, thus resulting in the production of
testosterone in male fetuses.
This small secretion of testosterone during
gestation is the factor that causes the fetus to grow male sex organs."
"NOTE:
basic internal sex is female; male development depends on hormone
> production (testosterone, DHT, and MDI" (Textbook of Medical Physiology,
by Guyton, 1986, ISBN 0-7216-1260-1, p. 956
*
"The default gender in the womb is female, which is perhaps hardly surprising given that the womb is an environment awash with female hormones.
A genetically male fetus will therefore develop the female form of sexual organs until ‘maleness’ is switched on by the SRY gene on the Y chromosome, and the fetal testis starts to develop and then produce testosterone. Incidentally a functioning ovary is not needed to appear to be female, whereas a functioning testis is essential for a man."
"You can look at gender in several different ways. Being XX or XY makes you female or male, of course, but there’s actually more to it than that. For instance, you could be genetically female, genitally female (i.e. you have a normal vagina), but if the hormones produced by your sex organs (gonads) have been more male than usual, these would influence your brain type and thus your sex-typical behavior.
Hormones Factors in Fetus Gender and Child Future Development | Health Doctrine
That part I highlighted and underlined in blue - is where the chemicals may or may not kick in correctly - causing a full spectrum of homosexuality and transgender people.
If chemicals do not switch on that SRY gene at the right time, - we get the full spectrum of homosexuality in the womb. And for some reason that percentage appears to be an advantage for the evolutionary advancement of humans.
*