For many centuries, doctors and scientists have tried to figure out what functional role certain organs play in the human body, at first glance, including the most useless of them: the appendix, coccyx, scalp or male nipples …
In his famous book The Origin of Species, Charles Darwin pointed to the "rudiments" of the human body that have survived through evolution. According to Darwin, these rudimentary organs served as one of the most striking proofs of his evolutionary theory: if earlier they were necessary for survival, then over time the need for them disappeared.
The presence of similar organs in two organisms of different species usually leads biologists to the educated assumption that these species had a common ancestor. Rudimentary organs allow tracing interspecies related relationships and give an idea of the evolutionary development of each species.
Rudiments are usually called "extra" organs or structures of the body, preserved in a degenerative or atrophied form.
Scientists explain the manifestation of rudiments by the long work of evolution: although the need for them has already disappeared, the genes responsible for their manifestation remain in human DNA for a long time.
The mystery of rudimentary organs has long worried many researchers, giving rise to a number of hypotheses and theories. Scientists are primarily interested in the questions of whether the rudimentary organs have preserved any functions that benefit the body, as well as what task they performed at a certain stage of evolutionary development.
In herbivorous vertebrates, the appendix is larger and very well developed. Its main task: to help animals digest large amounts of plant-based food.
The human appendix is a vermiform appendix located at the junction of the small intestine to the large intestine. The appendix does not directly participate in the digestion process.
Biologists are convinced that this vestigial organ came from herbivorous ancestors. As the paleontologist Alfred Sherwood Romer noted in his book "The Vertebrate Organism", the main benefit of having an appendix comes to surgeons, hinting at the huge number of appendicectomy operations performed annually when appendicitis occurs.
In 2000, there were nearly 300,000 such operations in the United States alone. At the same time, 371 deaths from appendicitis were also recorded.
Why do men need nipples?
The presence of nipples in men has long been the reason for numerous jokes and embarrassment. Many skeptics, questioning evolutionary theory, like to ask a mocking question: "Do you think men descended from women, since they still have nipples?"
Of course, this is not the case. It's just that both women and men have nipples at an early stage of fetal development. During this period, the fetus can be considered asexual; only with further embryonic development does a hormonal explosion occur, in which the sex of the child is formed. But the nipples in the embryo appear long before this moment.
In general, all mammals have mammary glands, regardless of gender. Male nipples can be considered rudimentary, although they can play a role in sexual arousal.
There are also cases where the breasts of men produced milk.Breast cancer, due to the presence of mammary glands, also occurs in men, although much less frequently than in the fair sex.
The tailbone is a series of accrete rudimentary vertebrae found in the lower spine of humans and other tailless vertebrates.
We inherited this rudiment from our ape-like ancestors with tails, which they, like many modern mammals, used to maintain balance, communicate and grab objects.
Since the ancestors of Homo sapiens learned to walk straight, the need for a tail disappeared, and this limb gradually, in the process of evolutionary selection, disappeared.
Many believe that the tailbone has a functional significance in the human body: it plays a role in the distribution of physical activity, especially when bending over a seated person.
However, there are many facts about successfully performed operations of surgical removal of the coccyx, which did not lead to any negative consequences for patients.
Sometimes children are born with a few extra vertebrae on the tailbone, that is, a small tail as an atavism. Such atavisms do not carry any negative consequences for human health, although, of course, in medieval Europe, such children were most often killed along with their mothers, like the offspring of Satan.
Piloerection occurs when peripheral nerve endings are stimulated, which are responsible for muscle contraction of hair follicles. In this case, the hairs on the human body rise, creating the effect of "goose bumps".
In animals covered with wool, this process is important: when stimulated as a result of aggression or fear, the hairs of the animal stand on end. To a potential enemy or victim, the animal seems much larger than it actually is, which brings certain advantages in survival or hunting.
People, having gotten rid of their hairline almost completely in the course of evolution, no longer need "goosebumps running on the skin" or "hair standing on end", but they still retain this rudimentary effect.
Of course, some part of the hair on the human body still has functional significance. Eyebrows, for example, successfully protect the eyes from sweat drops, and the hair on a man's face gives its owner certain advantages when meeting and courting women.