Over millions of years of evolution, the monkey descended from the trees and began to walk on two legs, has undergone many changes in its body.
She lost her thick coat, her brain increased several times, due to upright posture, the gluteal muscles and hips developed, the position of the head, the position of internal organs, etc. changed.
About 40 thousand years ago, man received his modern appearance, but his body still contains elements that were needed only by the primate living on trees, and even earlier forms of life.
The main rudimentary organs are usually called the appendix, male nipples, wisdom teeth. In fact, there are much more of them, and in this article we will look at six more.
Scientists generally do not know why these organs are still preserved in our country. It is possible that too few years have passed for their disappearance. And it's not a joke. Dinosaurs, for example, evolved over millions of years and modern man with his 40 thousand is just a crumb on the map of evolutionary history.
Third eyelid
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Third eyelid or nictitating membrane, in Latin Linea semilunaris. It is also called the Crescent fold. The man only has a tiny pinkish-red lump of flesh in the corner of the eye, close to the nose.
In many mammals, it has been preserved in the same rudimentary state, although there are those who have a full-fledged membrane, including polar bears, seals, and cats. It is also found in reptiles, birds and sharks.
The blinking membrane is designed to protect the eye from contamination, but in humans, movable eyelids actively cope with this.
In the human embryo, the nictitating membrane in its full form occurs only in the early stages of development, at the age of several weeks. And the embryo at this time looks more like a fish fry.
Palmar muscle
The long palmar muscle - Musculus palmaris longus - can be useful to a modern person only in one case, if he begins to use his hands for jumping from branch to branch like orangutans.
It is curious that this rudimentary organ in the human body has already begun to die off, that is, not every person now has it. To test if you have this muscle, close your thumb and little finger and lift them slightly.
If you see a long, tense tendon on the wrist, then you have this muscle, if you did not see it, then you are included in about 15% of those who have already lost it.
Darwin's tubercle
This rudimentary organ is usually very rarely remembered. This is because it is not even a full-fledged organ, but a tubercle on the inner side of the auricle.
If you look at photographs of common monkeys or macaques, you can see that their ears are slightly pointed, almost like those of elves. It is believed that the Darwin's tubercle is a rudiment of the pointed ear of primates.
Darwin's tubercle is also not found in all people, there are those who do not have it. There are also about 10% of those who have this tubercle on the outside of the auricle.
What was he needed for? It is believed that the pointed tip of the ear helped to enhance hearing and was combined with the ear muscles, which have almost completely disappeared in humans. In the course of evolution, it was more convenient for a person to turn his head in the direction of hearing when walking upright.
Goosebumps
Goose bumps or goose bumps - small frequent bumps in a person occur under several circumstances - strong fear, excitement, or as a reaction to cold. However, there is no benefit from them now.
According to scientists, goose bumps earlier, in the presence of hair on human ancestors, signaled danger, since they form around hair follicles and with fear, the hair literally stands on end.
A similar effect is also called the Pilomotor reflex and it occurs in other mammals. For example, a porcupine in fright because of this reflex thrust its needles into the enemy.
With the loss of abundant hair, this function has become completely useless.
Coccyx
The tailbone is several small bones fused into a single whole, located in the lower part of the spine. In many mammals, these bones are part of the tail, including tailed primates. Tailless primates have the same coccyx as humans.
A human embryo at the age of 4-6 weeks has a small tail, but in the interval from 6-8 weeks it disappears, and after it only the bones of the tailbone remain.
Despite being rudimentary, the tailbone still has enough functions. The muscles and ligaments of the organs of the genitourinary system, the large intestine and the gluteus maximus muscle are attached to it. It also plays a role in the correct distribution of the load on the pelvis.
Palmar grasp reflex
The palmar grasping reflex is one of the main reflexes that a newborn baby has. It is enough to bring an object to the baby's palm, he will grasp it tenaciously.
Such an instinctive reflex is vital for primates, whose cubs, soon after birth, begin to cling to their mothers' fur and are completely useless for a person who has not had this wool for at least 40 thousand years.
The same reflex also works when you touch the sole of the foot, after which the toes instinctively bend. It also comes from primates, whose toes grip a branch or hair as tightly as fingers.