During birth, as the shape of the human child begins to take form, a duck bill also is formed. In about a week, the bill will drop off and either attach to the infant's waist, or it will journey inside the anal cavity. If the bill attaches to the waist, it becomes a penis. If it does not, the child remains a female. Some anomalies may occur, such as attaching to the nipple. This will cause a disease known as Retardednippleemia
which is common if the woman who is pregnant has many sex partners. Another common defect that may occur is when two bills form and one bill tunnels up the anal cavity and the other one will attach to the waist. The male born will be homosexual. Another exception to this rule is when no duck bill forms which also causes the female to become homosexual. Science has recently proved this to be true.
Surprisingly, some doctors refuse to accept The Galvis Theory of Gender Decision, however Professor Rarington Rockwood has agreed with Galvis's theory for quite some time.