Study: Human hands are more primitive than chimpanzee limbs. Monkey species

Hand Our hand has several joints of varying degrees of mobility. The shoulder joint is a ball-and-socket joint, which allows the humerus to move in a wide range. It can spin like a propeller in almost any direction. The elbow joint

Mechanical arm Neil White and Paul Chappell have been developing a mechanical prosthesis for many years. At first he could only perform simple operations, such as opening a door lock with a key and opening a tin can. The fingers were activated by

How many fingers does a monkey have? and got the best answer

Answer from Lali Lali[guru]
Was the question asked as a joke? Then
- On two hands! - confirmed the Handicraft. - And the monkey has hands everywhere! - Chucha remembered, - how many fingers is this? - As many as legs! - he said, as the Handicraft cut off, then he thought and corrected himself... - how many notes!
Well, seriously speaking, it’s almost the same as ours, but not all species.
Their fingers and toes are very flexible, and their big toes and feet are covered with non-slip skin, similar to those of humans. Most monkeys have flat nails, but marmosets have claws, a feature they share with some monkey species.
Many monkeys have thumbs and big toes that are opposed to other fingers to adapt to trees and to grasp objects. However, this feature varies among varieties. Old World monkeys are usually dexterous and use their fingers to pick up fleas and parasites from each other. In contrast, New World monkeys lack such fingers on their hands, although they do have them on their feet. Interesting fact, one group of Old World monkeys - colobus monkeys - have no thumbs at all, but this does not cause them any inconvenience, and they, like other relatives, easily travel through trees

In most other mammals, the grasping organs are a pair of jaws with teeth or two front paws that press together. And only in primates the thumb on the hand is clearly opposed to the other fingers, which makes the hand a very convenient grasping device in which the other fingers act as a single unit. Here is a demonstration of this fact, but before proceeding with the practical experiment, read the following warning:

While performing the exercise below, bend your index finger and DO NOT HOLD middle finger with the other hand, otherwise you may damage the forearm tendon.

After reading the warning, place one palm on a flat surface, back side down. Bend your little finger, trying to touch it to your palm. Please note that along with the little finger, the ring finger also rose, and its movement occurs automatically, regardless of your will. And in the same way, if you bend your index finger, then your middle finger will follow it. This happens because the hand has evolved to grasp, and it is possible to grasp something with minimal effort and maximum speed if the fingers are connected to the same mechanism. In our hand, the gripping mechanism is “headed” by the little finger. If you set yourself the task of quickly squeezing your fingers one by one so that they touch your palm, then it is much more convenient to start with the little finger and end with the index finger, and not vice versa.

Opposite these fingers is the thumb. This is not uncommon in the animal kingdom, but in few groups this feature extends to all members of the group. Birds of the order Passeriformes have opposable digits, although in some species it is one digit out of four, and in others two digits are opposed to the other two digits. Some reptiles, such as the branch-walking chameleon, also have opposable toes. In invertebrates, prehensile organs take many forms—the claws of crabs and scorpions and the forelimbs of insects such as the praying mantis come to mind. All these organs are used to manipulate objects (the word "manipulation" comes from the Latin manus, which means "hand").

Our thumb is opposed to the other fingers only on our hands; in other primates this feature extends to all limbs. Humans lost the opposable toe as they descended from the trees to the ground, but the size of the big toe still indicates its special role in the past.

Compared to all monkeys, man has the most dexterous hand. We can easily touch the tip of our thumb with the tips of all our other fingers because it is relatively long. The chimpanzee's thumb is much shorter; they can also manipulate objects, but to a lesser extent. When monkeys hang and swing on a branch, their thumb usually does not wrap around it. They simply fold their remaining fingers into a hook and grab the branch with them. The thumb does not take part in the formation of this “hook”. A chimpanzee only grasps a branch with all its fingers when walking slowly along it or standing on top of it, and even then, like most apes, it does not so much grasp the branch as rely on its knuckles, as when walking on the ground.

Chimpanzee palm and human palm.

Primates have another evolutionary adaptation for manipulation on their hands. In most of their species, the claws have turned into flat nails. Thus, the fingertips are protected from damage, but the fingertips retain sensitivity. With these pads, primates can press on objects, grasp them and feel any surface, even the smoothest, without scratching it. To increase friction, the skin in this area is covered with fine wrinkles. This is why we leave fingerprints.

There is a common belief among people that Homo Sapiens is one of the most advanced species among numerous animals. As the results show latest research published in the journal Nature Communications, human hands are evolutionarily more primitive than those of chimpanzees.

A team of paleoanthropologists led by Sergio Almesija from Stony Brook University conducted a comparative analysis of the hand bones of humans, chimpanzees, orangutans, as well as early apes such as Proconsul Primate, and early humans, including Ardipithecus and Australopithecus sediba.

Scientists have concluded that since the last common ancestor of humans and chimpanzees, who lived on our planet about 7 million years ago, the proportion human hand practically did not change, but the hands of chimpanzees and orangutans developed. So from the point of view evolutionary development, hand structure modern man retained its primitive character, although traditionally scholars believed that it had changed to handle stone tools.

“Human hands have not changed much since the common ancestor of apes and humans. The human thumb is relatively long compared to the rest of the fingers, a trait often cited as one of the reasons for the success of our species, as it allows us to hold a variety of tools. It is much more difficult for monkeys to hold objects; they cannot reach the rest with their thumbs - but the structure of their palms and fingers allows them to climb trees. Chimpanzees' hands are much longer and narrower, but the thumb is not as long as ours."

In addition to humans, gorillas inherited a more primitive structure of hands; their feet are also similar to humans.

Almesija and his colleagues hypothesized that primates managed to survive the mass extinction at the end of the Miocene, 5-12 million years ago, because they specialized in certain habitats. While chimpanzees and orangutans became tree-climbing specialists, humans evolved to walk on the ground, just like gorillas.

A new study suggests that the small changes in the structure of the human hand occurred with the transition of hominids to upright walking, and not with the use of stone tools. Most likely, the ability to use tools in human ancestors was associated not with the structure of the hands, but with neurological changes and the evolution of the brain. It was the development of the brain that allowed hominids to learn to precisely coordinate the movements of the forelimbs, to comfortably grasp tools and subsequently master complex fine motor skills.

According to genetic research that has just been carried out, there are incomparably large differences between humans and apes.

Remarkably, human DNA allows us to perform complex calculations, write poetry, build cathedrals, walk on the moon, while chimpanzees catch and eat each other's fleas. As information accumulates, the gap between humans and apes becomes increasingly clear. The following are just a few of the differences that cannot be explained as minor. internal changes, rare mutations or survival of the fittest.

1 Tails - where did they go? There is no intermediate state between having a tail and not having a tail.

2 Our newborns are different from baby animals. Their sense organs are quite developed, the weight of the brain and body is much greater than that of monkeys, but with all this, our babies are helpless and more dependent on their parents. Gorilla babies can stand on their feet 20 weeks after birth, while human babies can stand only after 43 weeks. During the first year of life, a person develops functions that baby animals have before birth. Is this progress?

3 Many primates and most mammals produce their own vitamin C. We, as the “strongest,” apparently lost this ability “somewhere along the way to survival.”

4 Monkeys' feet are similar to their hands - their big toe is movable, directed to the side and opposed to the rest of the fingers, resembling the thumb of a hand. In humans, the big toe is directed forward and not opposed to the rest, otherwise we could, having taken off our shoes, easily lift objects with the help of the big toe or even start writing with our feet.

5 Monkeys have no arch in their feet! When walking, our foot, thanks to the arch, absorbs all loads, shocks and impacts. If man descended from ancient monkeys, then the arch of his foot should have appeared from scratch. However, a spring vault is not just a small part, but a highly complex mechanism. Without him, our life would be completely different. Just imagine a world without upright walking, sports, games and long walks!

Differences between monkeys and humans

6 A person does not have a continuous coat of hair: if a person shares a common ancestor with monkeys, where did the thick hair go from the monkey’s body? Our body is relatively hairless (disadvantage) and completely devoid of tactile hair. There are no other intermediate, partially hairy species known.

7 Human skin is rigidly attached to the muscular frame, which is characteristic only of marine mammals.

8 Humans are the only land creatures that can consciously hold their breath. This seemingly “insignificant detail” is very important, since an essential condition for the ability to speak is a high degree of conscious control of breathing, which we do not share with any other animal living on land. Desperate to find a land-based “missing link” and based on these unique properties humans, some evolutionists have seriously suggested that we evolved from aquatic animals!

9 Among primates, only humans have Blue eyes and curly hair.

10 We have a unique speech apparatus, providing the finest articulation and articulate speech.

11 In humans, the larynx occupies a much lower position in relation to the mouth than in monkeys. Due to this, our pharynx and mouth form a common “tube”, which plays an important role as a speech resonator. This ensures better resonance - a necessary condition for pronouncing vowel sounds. Interestingly, a drooping larynx is a disadvantage: unlike other primates, humans cannot eat or drink and breathe at the same time without choking.

12 The thumb of our hand is well developed, strongly opposed to the rest and very mobile. Monkeys have hook-shaped hands with a short and weak thumb. No element of culture would exist without our unique thumb! Coincidence or design?

13 Only humans have true upright posture. Sometimes, when monkeys are carrying food, they can walk or run on two limbs. However, the distance they travel this way is quite limited. In addition, the way monkeys walk on two legs is completely different from how humans walk on two legs. The unique human approach requires a complex integration of the many skeletal and muscular features of our hips, legs and feet.

14 Humans are able to support our body weight on our feet while walking because our hips meet at our knees, forming a unique 9-degree bearing angle with the tibia (in other words, we have “knees”). Conversely, chimpanzees and gorillas have widely spaced, straight legs with a bearing angle of almost zero. When walking, these animals distribute the weight of their body on their feet, swaying their body from side to side and moving using the familiar “monkey gait”.

15 The complexity of the human brain is much greater than that of monkeys. It is approximately 2.5 times larger than the brain great apes by volume and 3–4 times by mass. A person has a highly developed cerebral cortex, in which the most important centers of the psyche and speech are located. Unlike monkeys, only humans have a complete Sylvian fissure, consisting of the anterior horizontal, anterior ascending and posterior branches.