A mystery about a boy's

There is a very mysterious detail that scientists have always been looking for for a long time, and it has to do with your . "precious".

The human body still has many mysteries waiting to be discovered. One of the most annoying details is related to your . little boy, to be more precise of every male in the animal world.

The story is: why in almost all mammals, is the genitals always dangling in a very vulnerable place? The term "genitals" here includes not only the young boy, but also the two marbles (testicles) and the pouch (scrotum).

Why are these two things not made hidden in, like a woman's uterus and eggs?

Why leave in such a vulnerable position?

After many years of searching, experts now believe that they have found the answer. They are located in a number of animals whose testes are designed to hide in the abdomen, such as elephants, piglets (aardvark), and a group of mammals in Africa (afrotherian).

In fact, testicles work best if kept at a temperature slightly lower than the body temperature. However, this cannot be the reason, since the aforementioned animals still naturally reproduce even though the two stones are hidden inside.

Therefore, to verify, experts from Leicester University tested 71 placenta in scrotum-free species, in order to search for 2 types of genes RXFP2 and INSL3 . These genes are responsible for forming ligaments at the testicular stem.

As a result, both genes in these animals have mutated to an inactive phase.

The elephant has no scrotum.

The test also showed that the common ancestor of all African mammals (about 70 - 90 million years ago) had a testicular droopy, compacted in a scrotum bag. But for what reason did some species evolve to hide them?

Answers come from fossil molecules

According to Neil Adams, Ph.D. of molecular fossil at Leicester University, the process of examining mammal DNA in Africa may be a reasonable solution, since we do not need to know their relationship with groups. other animals. Instead, they just need to find evidence that their genes have evolved.

They realized that only modern mammals in Africa have an evolutionary version of the gene. Most other groups only have original genes. It means that, in some species in Africa, although there are no scrotum bags, the two genes RXFP2 and INSL3 still exist.

This proves that their ancestors sought to reproduce these two genes. But then in the process of evolution, for some reason they realized that letting "dangling" testicles be of no use, these two genes also mutated to be useless, leading to the scrotum pocket also turning lost.

Only modern mammals in Africa have an evolutionary version of the gene.(Illustration).

And since this disappearance has no effect on fertility, they are still circulated for generations to come. The experts even identified the moment when the mutation appeared, thanks to the technology of molecular clocks.

But why is this an important finding?

When identifying an original gene, we can determine which mutations occur in many animal groups. We can even know how much time it will take for this evolutionary gene to work for an entire species later.

Still, experts still don't know why some species evolved that way. It may be because of some benefits, but it is currently unknown.

But in return, the use of molecular clock technology in biology can help us know what extinct species look, even if no intact fossil is found.