There seems a logical explanation about why women have nipples – to breastfeed babies. Unlike women’s nipples, men’s can’t feed babies. So why do men have them? There’s a surprising answer to this question.
ALL BABIES IN THE WOMB GROW AS FEMALES – YES EVEN THE BOYS!
As embryos in the womb, males and females have similar tissues and body parts, which is why nipples are present in both sexes. It is the effect of the genes, the Y chromosome and the hormone testosterone that brings about the masculine changes to the embryo.
Females have two X chromosomes, while males have an X and Y. XX fusion results in the child being a female while XY results in the child being a male. But as an embryo, everyone starts out females. It’s that Y chromosome that makes a man a man.
If the embryo is genetically male with a Y chromosome present, after six weeks it begins to develop the male characteristics, when a special part of the Y chromosome, called the SRY gene, gets activated. This initiates the development of the male parts. It is then that the male and females start to differentiate. But nipples start to develop before this differentiation occurs – at about five and a half weeks. So even though the embryo becomes male, it is still left with nipples and some breast tissue.
In simple words, men have nipples because they already had them before they became male.