Atavisms are one of the most interesting and mysterious topics for study in biology, since on the one hand, they make it possible to recognize the ways of communication of modern man with the natural world, and on the other, they make it clear what our ancestors were and how they lived. These phenomena are characteristic not only of man, but of all other representatives of the wildlife world, because we all change over time in order to better adapt to the changing environmental conditions.
What is atavisms
Atavism is a fact of the appearance in a particular type of organism of certain signs that were characteristic of their ancestors, but were lost in the process of evolution. Their appearance is due to the fact that DNA does not lose over time those genes that are responsible for these traits, although in most cases their manifestations are blocked by repressor genes. Thus, if suddenly the action of the repressor disappears or decreases, atavisms in a person and any other creature arise again.
Examples of atavisms in humans
The human body is a complex system in which each cell serves to perform certain functions. But a detailed examination reveals that this is not always the case, and the examples of atavisms in humans clearly demonstrate this.
Appendix
Surely every person at least once in his life heard about this vermiform appendix of the intestine. Previously, it was necessary for the accumulation and storage of cellulose and took part in the hematopoiesis process, more precisely in the production of white blood cells, but over time, people began to consume more refined products and the need for an appendix disappeared. Currently, it often becomes the reason for the operation to remove it due to developing inflammation. There are cases when he was absent altogether.
Muscle
Far from always, atavisms in a person are associated with specific organs, in fact it can be any part of the body. Despite the fact that his life has changed a lot, his body still has a large number of muscles that are no longer used for its intended purpose. For example, the appearance of the ability to at least slightly move the ears is attributed to human atavism, which his ancestors could probably do in order to better catch sounds during hunting. Also, human atavisms are manifested in the form of the presence of the subclavian and palmar muscles, as well as the plantar muscles, although he can use them in order to write or lift small objects.
Coccyx
Atavism also includes the presence of the tailbone, which once was probably the tail. Sometimes atavisms in a person cause him more inconvenience than benefit, as in the case of the coccyx, since he does not bear any functional load, but his fracture or damage is very painful.
Goosebumps
The sensation of goosebumps occurs in a person in a variety of situations under the influence of external and internal stimuli. In fact, the feeling of goosebumps is exactly what we see, for example, in cats and dogs at the sight of enemies, that is, bristling. A modern person has much less hair on his skin than other mammals and his distant ancestors, so we can’t bristle fully.
Nose
It is impossible to call the nasal cavity a full-fledged atavism, but sometimes atavisms in a person are partial. The scent of a modern person is far from being as good as the scent of his ancestor, although until now some people have a more acute sense of smell than others, which allows them to work in the field of perfumery and become unique specialists.
Sometimes science cannot say for sure whether this or that sign is atavism, but, perhaps, with the course of evolution, nature will reveal all its secrets to man. Currently, we can only speculate and imagine, hoping to get confirmation of our fabrications.