ALL MEN ARE ORIGINALLY FEMALES.

Photo By An and Zivkan

Scientists have discovered that men are created from a female blueprint and in fact, if you don’t have a sex chromosome or any one of the sex chromosomes, you come out as a girl, which is the default phenotype.

As you may already know, the real difference between men and women is that men have XY chromosomes while women have a pair of X chromosomes. It is actually a tiny gene on the Y chromosome that transforms the foetus into a male. This gene is called SRY (Sex determining Region Y). The SRY kicks in when the embryo is around six weeks old, but until then the baby could become either male or female. During gestation, the cells of the primordial gonad are in bipontential state --- they have the ability to become either male cells or female cells. It is the SRY gene that, then, initiates testis differentiation by activating DNA-binding proteins that allow these cells to differentiate and proliferate.

In other words, the SRY that gives instruction for the development of testis in the foetus and without its influence, the baby (whether having XX or XY chromosomes) will not emerge as a boy, but as a girl. Take for example, if there is by any way mutations in the SRY, the baby becomes an XY female with gonadal dysgenesis; this condition is also known as Swyer Syndrome. There is a similar condition called AIS (Androgen Insensitivity Syndrome). This is where the body of an XY-carrying embryo doesn't respond to androgenic hormones released under the influence of SRY gene. In both conditions, the foetus assumes the default position, which is female.