All other human fingers have three segments, why is the thumb the only one with two segments?

Scientists believe that this structure is most suitable for it. Because if the thumb is only composed of one section, it is very inconvenient to grasp objects with the other four fingers; If it is three sections, then it will appear weak and incapable of some powerful movements.

A human hand has 5 fingers, which vary in length, thickness, and thickness, and each finger has its own name: thumb, index, middle, ring, and little finger. According to the theory of evolution, it is already known that man evolved from Australopithecus.

Australopithecus lived in forests and crawled on all fours, with the thumb or big toe separated from the other four fingers (toes), and when climbing in trees, it was very suitable to have 3 fingers or toes, while only 2 thumbs (toes) were of little use. Later, the apes learned to walk upright, and their upper limbs were liberated, especially after they evolved into humans, and their thumbs became very thick and powerful due to the frequent use of tools in their hands.

When Australopithecus evolved into humans, their thumbs became very thick and powerful due to the frequent use of tools in their hands. In the palm of the human hand, some well-developed thenar muscles are also produced, allowing the thumb to move in tandem with the other four fingers opposite. It is the result of this evolution that the thumb of modern humans has become the most powerful finger.

The idiom "second to none" means the most outstanding, that is, the thumb. Indeed, according to scientists, almost more than half of all jobs that involve finger movement require thumb help. The thumb works both independently and in tandem with the other four fingers.

Scientists believe that this structure is most suitable for it. Because if the thumb is only composed of one section, it is very inconvenient to grasp objects with the other four fingers; If it is three sections, then it will appear weak and incapable of some powerful movements. Therefore, this structure of the thumb is one of the reasonable results of the evolution from ape to man.

The thumb is the most powerful of the five fingers, if it is three sections, it is like several other fingers have no strength, if it is one section, it cannot be bent, it is very constant, so, the two sections of the thumb are the result of human evolution.

Because the thumb only plays an auxiliary role when moving, the thumb is two segments.

In this way, the thumb is more powerful and more comfortable and convenient when extracting things, and it will not be overwhelmed.

Facilitates the use of tools. The other fingers of each hand have three joints, only the thumb is two, which is also the result of human adaptation to nature, in order to better match the other four fingers to complete the grasping, grasping and other movements.

If the thumb only has one side reed, it will not be able to bend it significantly, and it will not be flexible enough to cooperate with other fingers to complete complex tasks. If the thumb is three-segmented, the flexibility is enough, but the grasping and grasping forces are dispersed, making the strength insufficient. Therefore, only two sections of the thumb are the most appropriate.

The biological evolution of the thumb is based onThe fact that the thumb has only two segments is also associated with upright walking in humans. In the process of human evolution, bipedal walking has become an important evolutionary feature. This way of walking increased the opportunities for human hand movement, and the human hand gradually evolved as humans no longer sat on all fours, but used their hands to grasp and support.

In our daily life, we can also find that according to the development of our human body structure, we can know that our thumb has always only had two bones, which is completely different from other fingers, which have three bones while our thumb has only two. Many people are very confused about this phenomenon, and at this time we can explain the appearance of this phenomenon according to the development of our human body and the role of the thumb.

We often use our palms and fingers in our daily lives. When we use our fingers, it's basically scratching an itch or carrying a book for us. At this time, we can find that due to the different growth directions, the thumb can not actually play any role when carrying things.

But when we press the button or play with the mobile phone, the role of the thumb is relatively very prominent, due to the special growth direction, the role of him and the other four fingers is completely different. Through comparison, we can find that the strength of the thumb is completely different from the strength of the other four fingers, and we found that the strength of the thumb is much higher than the strength of the other four fingers, so we will let the thumb press various buttons or stabilize various items in daily life.

In fact, for us, the role of the thumb is not only to carry, hold, and press the object, but also to maintain a balance of the things in our hands. If our thumb is made up of three bones at this time, then it is easy to use the same force as the other four fingers when exerting force, which makes it difficult to ensure that we use our thumb to maintain balance when holding things.

Therefore, at this time, we have explained why the thumb is composed of two bones from three perspectives: the growth of the thumb and the structure and function of the human body. In fact, in essence, we must also believe that all the structures of our human body are very meaningful and valuable.

I think it's a normal physiological phenomenon, and everyone has two thumbs, and it's also related to bone development, so I don't think it's one or three.

This is because the thumb is shorter than the other fingers, so it is two-jointed, and if it is one or three, it is not as flexible as two-section, nor is it more labor-saving than two-segment.

Because the length of the five fingers of human beings is different, in the long process of biological evolution, the thumb evolved to be relatively short, so it is two knuckles.

Our ancestors, Australopithecus, used their limbs to climb up and down trees and pick fruits. At that time, the thumb, like the other four fingers, had three knuckles. This structure makes it easy to grasp the trunk and allows the ape to move flexibly between the branches.

Later, a part of Australopithecus learned to walk upright. The main function of the upper limbs has changed from climbing to using tools. The evolution of a long period of time has given us a clear division of labor for each of our fingers.

You don't see that the thumb has only two segments, but it is the most powerful of the five fingers. If the thumb has three segments like any other finger, it will not be able to perform a large force operation. The two-segmented thumb can be combined with the other four fingers to perform a variety of hand movements, and can also work independently.

Its function accounts for 40% of the function of our entire palm! Without it, there are many tools that we wouldn't be able to use. Imagine:

How do you use scissors without a thumb?

So where did the third finger of the thumb go? In fact, if you look at the X-ray photos of the hand bones, you will find that the original third finger gradually moves towards the palm and becomes the "metacarpal bone" connected to the palm.

<>1. According to the theory of making and making factions, it is already known that man evolved from the ancient ape. Australopithecus lived in forests and crawled on all fours, with the thumb separate from the other limbs, and only two thumbs of little use, but commanding.

2. It is the result of this evolution that the thumb of modern humans has become the most effective finger. The meaning of the idiom "second to none" is to refer to the thumb.

3. There are only two thumbs in such a heavy mountain, and scientists believe that this structure is the most suitable for it. Because if the thumb is only composed of one section, it is very inconvenient for it to cooperate with the other limbs to grasp my objects.

4. If the thumb is three-segmented, then it will appear weak and powerless, and it will not be able to perform some powerful movements. Therefore, the structure of the thumb is one of the reasonable results of the evolution from ape to man.

The fingers are all three-jointed, and only the thumb is two-jointed. This structure is the inevitable result of human evolution. The ancestor of man was an ape, and after the ape began to walk upright, the original upper limbs were no longer responsible for walking, and the lower limbs were dedicated to weight-bearing walking.

The thumb is progressively longer and more powerful, and there are several well-developed thenar muscles that allow the human thumb to move with the other four fingers. In order to adapt to the palmar movement of the thumb, so that the thumb can be extended, flexed, retracted, rotated, etc., the optimal structure is the two knuckles. This structure is actually best suited for thumbs.

The index finger, middle finger, ring finger and little finger of the human hand are divided into three segments, but the thumb has only two segments, which is the inevitable result of long-term human evolution, in order to make human hand activities more flexible and powerful, and is a manifestation of human evolution to adapt to the environment.

Before I saw this question, I really didn't think about why this is, because we are born like this, and the people around us are like this, so naturally there is nothing worth thinking about. In fact, the reason for this problem is relatively simple, it is the result of natural evolution. Let's imagine if your thumb has also become three sections, then it becomes less convenient when doing things.

Therefore, it is very beneficial to our daily life if the thumb is two sections, and if it is all three sections, it is not very convenient for the fingers to grasp and be hungry. And in the long-term evolutionary process, there is also a ** muscle in the palm of the human hand, which allows our thumb to work alone.

Stretch out the palm of your hand and find that our other fingers have three sections, only the thumb is two, why is this, it's very simple, we can be smarter than monkeys, and the degree of evolution is hundreds of lifetimes more than they don't know, so monkeys only have two sections, do you still want three?

In fact, it is a biological evolutionary phenomenon that we only have two sections of our fingers and thumbs, if you try it, if there are three sections, can you still easily hold a thing? This kind of evolution is hard-won, it has gone through a long evolutionary process, so the most reasonable status quo has appeared in us, there are many primate thumbs that are also two-segmented, three-segmented little fingers, this biological phenomenon is very magical, isn't it?

The index finger, middle finger, ring finger and little finger of the human hand all have three segments, but the thumb has only two segments, in fact, this structure is the most suitable for the thumb.

Because if the thumb is only composed of one section, it is very inconvenient to grasp the object with the other four fingers; If the thumb is three-segmented, then it will appear weak and incapable of some powerful movements.

Australopithecus crawls on all fours, with the thumb or big toe separated from the other four fingers (toes), and when climbing in trees, the three fingers or toes are very suitable, while the two thumbs (toes) are not very useful. After the evolution of Australopithecus into humans, they walked upright, their upper limbs were liberated, and their thumbs became very thick and powerful due to the regular use of tools. In the palm of the human hand, a ** muscle is also produced, so that the thumb can cooperate with the other four fingers.

The thumb works both independently and in tandem with the other four fingers. Therefore, we now have three fingers, but only the thumb is the result of human evolution.

Answer 1: This is how Nuwa designed it when she created man or God created man, and the original cannot be modified (this answer is legendary).

Answer 2: Human beings have gradually evolved to "revise" their body shape and body structure in actual life and labor, and have met the needs of a comfortable, coordinated body to meet the needs of daily actions.

If it is three, the thumb will appear weak, so that it will not be able to lift heavier objects; If it only has one section, it won't be able to grasp things with the other four fingers!

This may have something to do with human evolution.

This is the result of human evolution, so humans are much smarter than all animals, including monkeys.

The thumb is two sections that are easy to move, and the other fingers are three sections that are also the most convenient to move!

Because if the thumb is the third sister's, it won't be exactly the same as anything else.