Maybe we’ve never thought about it before, but there are things that we actually say when we think about it. One of them is the breasts found in human females. The breast size of human females begins to grow during puberty, regardless of pregnancy. Breasts that grow in a round shape continue to remain there even if no birth is given. So, what could be the reason for this round and large breast, which belongs only to the human female among all mammals?
Today we’re going to explain to you why human female breasts are permanently large and round, according to science. There are some theories on this subject, but we can say that the theory that scientists focus on the most is the breast structure formed due to sexual selection.
Why do breasts that form at birth in other animals become pre-enlarged and rounded in human females?
We humans are mammals in the primate order. Mammals feed their young with the milk they secrete. For this, they need breasts. When all mammals, from monkeys to dogs, become pregnant, their udders begin to enlarge. When the puppies are fed with milk and the task is completed, these breasts shrink again. In the human female, however, the situation does not work this way. There are some reasons why human females, whose breasts start to grow when they reach puberty, go through a different process than other mammalian females.
First of all, there are several theories about the large breasts of human females, but one in particular stands out. We might think that udders supported by sebaceous glands seen in human females create a reproductive advantage on the grounds that they increase milk production, but this theory alone does not find a response. Because other mammals and primates can also produce enough milk for their young.
Human female udders are actually not very suitable for offspring.
The large, rounded udder in human females should provide a distinct advantage, because the drooping udders seen in primates such as monkeys provide an easier comfort zone for the young to get in their mouths and suckle. Moreover, round shaped breasts make it difficult for puppies to take the breast to their mouth to drink milk, and also narrows the airway of the pup. When we look at all this, we see that the pre-emergence of the udder in human females does not depend on the offspring. At this point, the most accepted theory is sexual selection.
The fact that humans began to walk on two legs also affected sexual selection. As a result, the breasts of the human female began to replace the hips.
Standing on two legs, perhaps one of the greatest strides of the human species, may have caused the breasts to emerge in large and rounded shapes in human females regardless of pregnancy. You may ask how this is possible. Primates other than humans are rarely able to stand on two legs, although we often see them on all fours. This makes it easy for the male to approach the female from behind during sexual intercourse. For example, in monkeys, females may experience growth around the hips and reddening where the genitals are. This is thought to be due to sexual selection. Here, the monkey female indicates to the male that it is suitable for reproduction.
In humans, the situation changes with standing on two legs. For the person who takes an upright posture, sexual selection also begins to change. Where previously only hips were important for sexual selection, breasts are becoming more important sexually in people who stand up. As people stand on two legs, sexual intercourse begins to take place by looking face to face. However, as the vagina begins to come forward in women, the breasts also grow and become rounder with sexual selection. With this advantage, breasts replace the hips that go out of sight as a result of standing up.
Currently, the most accepted theory about breasts in human females is due to sexual selection. Human females with fat deposits in both the hips and breasts are preferred by males during sexual selection and become dominant over time.
Today we explained to you why human females have large and round breasts after puberty compared to other mammals. If you want more content like this, you can share it with us in the comments section.
Source: Livescience, Discover, ScienceDirect, Insider, Bilimfili
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