It's embryology: All humans start off as essentially female in the womb no matter what your chromosome arrangement is. After several weeks, if you have a Y chromosome, testosterone kicks in and it changes the chemistry in the genitals and the brain. But the nipples are already there...so they stay.
Answered 6/3/2016
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A doctor has provided 1 answer
A doctor has provided 1 answer
A doctor has provided 1 answer
A doctor has provided 1 answer
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