|Ouch, dat must chafe somethink awfull.|
Why do men have nipples? From an evolutionary context, this is an interesting question. In the female mammal nipples have an adaptive function, but in the male, they function, not at all. In fact, why do people, both men and women, have extra nipples? This question interests me as I'm endowed with an extra nipple like appendage.
Early embryonic development is a universal template and until the 6th week of gestation, the embryo is a blank tableau. Hormones at that stage kick in and the foetus will either develop along the female or male pathway. Divergence is in our chromosomes. The presence of the SRY gene on the male Y chromosome is the key. Without the expression of SRY at a critical stage in development, the default pathway is female. Therefore, men have nipples because the original design plan incorporates nipples. For nipples to disappear from the male anatomy there would have to be a selection process against male nipples. Evolution is lazy. If the appendage is not an impediment to reproductive fitness it will linger like a fart on an airless day. Male nipples confer no adaptive advantage or disadvantage for that matter. Not so much as a vestige but a slight impediment. The same argument applies to why women have orgasms. What interests me as a biologist and a man, is why women's orgasms are so hard to achieve, in comparison to the male variety, and when they do cum why it seems more exquisite than mine- I know, it is all about me.
So coming back to the extra nipple. Of course, there is the possibility of other extra body parts; extra toes; fingers; even whole reproductive organs are possible, though rare. Actually, extra nipples are not that rare and occurs in 1 in 500 of the population and interestingly, there is a male bias. Some perturbation during early embryonic development is to blame. Perhaps a variation on the design plan is at fault and interrelated to our evolutionary past when our ancestors were equipped with eight teats? Tis nothing to get worked up about, although past girlfriends have found it fascinating. Believe me, when you are living with said extra appendage, 24/7, the novelty tends to wear off.
For those that care: my supernumerary nipple is identical to that of the regular nipple, including hyperpigmentation, slight hyperkeratosis with epidermal thickening, pilosebaceous structure of Montgomery areolar tubercles, smooth muscle bundles typical of the areola.
So my variety of extra nipple is inert just like the other two, however, in women, the extra pleasure knob can be functional. To be totally gratuitous I'm going to slide off topic and consider gynaecomastia. This is a very common condition in males, especially overweight males and is often linked to hormone imbalance. These individuals are subject to 'female like' breast growth and it can be very distressing for those affected. To be honest, if I had this condition, I wouldn't get out of bed in the mornings.......