Chapter 20 Man is an animal ①

The world we live in is a material world, which is constantly moving, changing and developing. ① Originally contained in "The Origin of Man", China International Broadcasting Press, 1991 edition. The material world is composed of inorganic matter, organic matter, and organic living things.Organisms are living entities with metabolic functions.In the long process of evolution, it has formed a huge biological kingdom from simple to complex, from low-level to high-level.Although all living things are different in size and shape, they can all be studied scientifically. First, they are established as basic units called "species" or "species".Members of each species can freely mate and produce offspring with fertility, while members of different species cannot freely mate in the natural state. The theory believes that everything beyond the scope of experience is a priori He said that even if offspring were produced through marriage, these offspring were sterile.

Species with close kinship have many similar characteristics, thus forming a larger taxonomic unit - "genus", which can form a larger unit "family" from the "genus" level, and further followed by "order", " Gang" and "door".Sometimes such a classification level is not enough, and there are sublevels or superstructures such as "sub", "super", such as "subfamily", "superfamily" and so on. For each animal or plant, as long as the phylum, class, order, family, genus, and species it belongs to are clear, its position in nature is also clear.

In this chapter, I will first tell you clearly that man is an animal.Human beings are animals. Doesn’t it blaspheme human beings to say so?No, I'm just stating the true colors of people.Man is indeed an animal and the roles played by various classes have been scientifically analyzed, and the experience of this revolution has been summarized. , You see, his flesh and blood body, his breathing, digestion, excretion and reproductive functions, is there anything like an animal? So, in the eyes of zoologists, what kind of animal is modern man?Let's explore. 1.All kinds of people in the world belong to the same species.

Scientists can study humans in the same way they can with other animals.He would describe people like this: Height: Adult individuals range from 1.2 meters to 2.0 meters. Skin and hair color: It varies a lot, from light to black. Hair: In addition to armpit hair and pubic hair, most people have less hair on other parts of the body; the hair is long, and adult men have beards. Mode of action: Walk upright. Diet: Mixed food, the food includes fruits, vegetables and meat, usually cooked food. Distribution: Available all over the world. All human beings in the world, despite being yellow, white, brown, and black, belong biologically to the same species.This is self-evident, because different races can marry freely, and the mixed-race children born will all have normal fertility when they grow up.Modern humans belong to the same species in biology, the species name is "Homo sapiens", the Latin literary name is Homosapiens, here Homo is the genus name, which means "Homo", sapiens is the species name, meaning "wisdom", together The meaning of "wise man", referred to as "Homo sapiens".

Don't be surprised if yellow-skinned Chinese, white-skinned French, dark-skinned Congolese and brown-skinned Australians walk hand in hand in Tiananmen Square, although there are quite a few differences in skin color and appearance. , but biologically belong to the same species - Homo sapiens. 2.Humans are vertebrates. All animals can be divided into two categories according to whether they have backbones (spines) in their bodies. Those with backbones are called "vertebrates", such as fish, frogs, snakes, birds and dogs; those without this structure are called "no vertebrates". vertebrates" such as butterflies, spiders, and snails.

The spine is made up of many individual vertebrae joined together, and it is the backbone of an animal's body.With it, the animal's body becomes strong and powerful, and it also protects the spinal cord and internal organs.Another important feature of vertebrates is that their nervous system is highly developed, with the differentiation of the brain and spinal cord. The appearance of the brain is remarkable, because only with the brain can there be the material basis for high-level thinking activities. If you touch your back, you will find that we also have a backbone, so humans are also vertebrates.

All vertebrates share these basic traits and have evolved from a common ancestor. 3.Humans are mammals. Vertebrates can be divided into fish, amphibians, reptiles, birds and mammals, each of which has some common characteristics, so that some blood-related animals form corresponding categories. Among the vertebrates, there is a kind of hair, with a layer of fat and sweat glands under the skin, so that it can maintain a constant body temperature.Their middle ear has three separate small ossicles, the pedal, malleus, and incus.In particular, females have well-developed mammary glands, and their cubs are fed milk by their mothers after birth. Such animals are mammals.

Don't humans have the same characteristics?So humans are mammals too.Therefore, man's blood relationship with cattle, sheep, and rabbits is much closer than his relationship with fish and birds. Humans and all other mammals share traits common to mammals, and so share a common origin. 4.Humans are primates. Mammals can be divided into various groups, one of which is very special. Their fingers and toes have shoulder armor instead of claws; their big finger (or big toe) can touch the other four fingers (or toes) ), thus having the effect of anti-palm (or (foot concubine)).They have four incisors on each of the upper and lower jaws. In addition, they have advanced stereo vision. These mammals are called primates.

Primates include many species, including various monkeys and apes. Primates are divided into two categories by zoologists: prosimians and apes. The former are low-level monkeys, such as lemurs and tarsiers; apes together.The characteristics of apes are: the body is enlarged, the position of the eye sockets on the face is moved outward to the sides, which greatly improves the vision, and the temporal fossa is separated.In addition, they have a strong inquiry psychology and strong curiosity, and are often in an excited and restless state. Look at our own fingernails (toenails), look at our teeth, grasp something with our hands, and the unstoppable curiosity, the more mysterious the more the mentality to explore... It is not difficult to find that we Like other members of the primate class, there are no exceptions, so we are also primates and are included in the broad category of apes.

Humans share many characteristics with other primates and therefore share a common origin. 5.Man is also a kind of ape. Although apes and monkeys belong to a large category, there are obvious differences between apes and monkeys in appearance. Monkeys have tails, cheek pouches, and gluteal warts-the exposed corpus callosum on the buttocks.Apes (except gibbons have gluteal warts) do not have these characteristics of monkeys, but have their own characteristics: For example, the lower molars of apes have many cusps separated by "Y"-shaped grooves, while the cusps of the lower molars of monkeys are double-ridged; on either side of the shoulders, but on the back side.

Humans are very similar to apes, not only in the above-mentioned appearance characteristics, but also in the internal structure.For example, the arrangement of bones, muscles, and internal organs, and the characteristics of the brain, placenta, and appendix are both similar.Humans and apes have similar blood types that other animals, including monkeys, do not. The similarity in body structure often reflects the similarity in functional activities.According to the research of some scientists, humans, like apes, used a similar way of action "arm walking method" in a certain period of time in ancient times, that is, swinging with both arms, moving between trees like a swing. All apes, including humans, have adaptive characteristics of arm row, which are mainly reflected in the part of the body from the neck down to the waist above, and also reflected in the structure of the arms and hands. For example, they have long arms and elongated hands with hooked fingers and relatively small thumbs.The human hand is adapted to use and operate tools, and the thumb becomes longer, but the entire palm can still be used as a hook grip.The heads of their upper arm bones (ribs) face inward, and the shoulder cavity that receives the humeral head opens outward; while the humeral head of monkeys walking on four legs faces the rear side, and the shoulder cavity faces forward. Humans and apes have very broad shoulders, which increases the range of motion of the arms and facilitates arm movement.They have a long and thick collarbone, a short, flat and wide sternum, the entire chest is widened, and the anteroposterior diameter is shortened.The thoracic portion of the spine is curved inward, and the scapula is located dorsally.In addition, the lumbar spine is also shortened, and the two lowermost lumbar vertebrae heal with the sacrum.The shortening of the loin, bringing the chest closer to the pelvis, and the disappearance of the outer tail facilitate the trunk's swinging action in the tree.Of course, the muscles of the shoulders are also reshaped and strengthened by adapting to the arm row. Now the science has not fully clarified whether the adaptive changes in the arm-to-arm movements of humans and apes are inherited from a common ancestor, or developed independently to adapt to the same way of action? In recent years, with the development of molecular biology, it has developed from macroscopic research on anatomy, physiology and tissue embryos to microscopic research on the microstructure of cells, and even explored the blood relationship between humans and apes at the molecular level. . From the perspective of molecular biology to study the origin of human beings, a new branch of the discipline - molecular anthropology has emerged.According to the new data of molecular anthropology, science has more evidence to prove that there is indeed a close blood relationship between man and ape. For example, there is a protein called "hemoglobin" in the blood of all primates, and its function is to transport the oxygen drawn by the lungs to the tissues of various parts of the body.Protein bodies are composed of amino acids, and there are 20 kinds of amino acids in total. Different protein bodies are formed by linking different numbers of amino acids in different orders. These amino acids are first linked into a chain structure called a peptide chain, and then are combined into protein bodies. It is now known that mammalian hemoglobin is composed of 4 peptide chains consisting of 574 amino acids.There are two kinds of peptide chains in the hemoglobin of various primates, one is called Alpha (α) chain, and its variation is not very large; the other is called Beta (β) chain, this chain in primates variation is significant.However, in this chain, the difference between humans and apes is far less than the difference between humans and monkeys, indicating the close blood relationship between humans and apes. Molecular anthropology also explores this blood relationship from biological genetic material. The genetic material of organisms is mainly nucleic acid, and the genetic characteristics of organisms are mainly determined by nucleic acid. The carrier of genetic information is deoxyribonucleic acid (DNA). DNA mainly exists in a filament called "chromosome" in the nucleus. According to research, human somatic cells have 46 chromosomes, great apes have 48, and gibbons have 44.The number of chromosomes in apes is very close to that of humans.Studies have also shown that the DNA structure of black apes is only 2.5% different from that of humans, while the difference between monkeys and humans is more than 10%. Great apes are indeed similar to humans, so it is no wonder that they have long been called "anthropoids", which means "human-like apes".In fact, on the other hand, humans and apes have so many similar characteristics, in a sense, humans are also a kind of ape, and it is no wonder that in biological taxonomy, humans and apes are united as one, and together they are "humanoid". A member of the "Superfamily" or "Superfamily". As early as more than 100 years ago, the great British evolutionist Darwin put forward the theory of "common ancestor of man and ape" based on the scientific evidence at that time. He believed that the similarity between man and ape is so great, which shows their close relationship. Blood relationship and common origin, they come from a common ancient ancestor - the ancient ape, and the modern apes are human cousins. Modern scientific research shows that this theory is credible. From the perspective of biological evolution, it is not too much to say that humans are also a kind of ape. man is special animal Although man is differentiated from the animal kingdom, he is not an ordinary animal.Man is a special animal, with a high degree of self-consciousness and initiative, and is the most social animal.Human means human society, and human society is composed of individuals. Human is not only the product of the long-term evolution of the animal kingdom, but also grows up in the environment of human society.Therefore, when we talk about people, we are not only talking about biological people, but also about social people. 1.The essential difference between man and ape There are significant differences between humans and ordinary animals.Man can make and use tools, engage in productive labor, and create new living conditions for himself that did not exist in nature before. Man can carry out complex thinking activities, has self-awareness, and produces conscious initiative, so that man can dominate the natural world through the changes he makes, forcing the natural world to serve his own purposes.Especially after the emergence of human society, the development of human beings has not only gained a new and powerful impetus, but also gained a more definite direction, making him far surpass the animal kingdom and become the master of the natural world. If we compare human society with ape groups, the essential difference between humans and animals is even more striking: Human society (mainly discuss primitive society) 1.The essential characteristic is the social nature of human beings. Human beings have self-consciousness and self-awareness. 2.Subordinate to the basic laws of social development - the contradictory movement of productivity and production relations, promote the metabolism of the old and new society. 3.Relationship with the natural world: Can dominate the natural world, use tools for labor production, and create new living conditions for themselves. Group of apes (as ordinary members of nature) 1.The essential characteristic is the biological nature of animals, and apes do not have conscious agency and lack self-awareness. 2.Subordinate to the basic laws of biological evolution - the interaction of heredity and adaptation promotes species changes and promotes the evolution of the biological world. 3.Relationship with nature: using only nature, adapting to environmental conditions through changes in the body itself. Here, we can see that the sociality of human beings is the essential characteristic of human beings, and thus the "human nature" factor that distinguishes human beings from animals arises.However, after all, human beings were born out of the animal world and were born in the natural world, because human nature (the "beast nature" factor) is the basic stipulation of human beings that human beings cannot get rid of.From here we can say without hesitation that the essential difference between man and ape is that the latter is a pure animal creature, while man is a special creature that combines highly social and natural attributes, and is born of the coexistence of human and animal elements. Beings that interact with each other, the degree of human civilization, that is, the degree to which humans are far removed from the animal kingdom, depends on the ratio of human and animal factors, which was also expounded by the founders of Marxism. 2.Human characteristics reflected in body structure As a special animal, what is the biggest difference between him and apes in terms of body structure, that is, in terms of physique?There are generally recognized three points: Modern man has a habitual upright posture and the ability to walk upright on two feet; the snout is shortened, so the face is flat; and he has a large brain. Modern apes are accustomed to a semi-upright posture and four-legged (occasionally two-legged) walking; the snout is prominent, so the face is lordotic; and the brain size is relatively smaller. Humans have evolved to adapt to life on the ground.There are many explanations for how a person's upright posture came to be, one of the main factors being adaptation to handling tools with two hands.Due to being upright, it causes corresponding changes in many parts of the human body, such as the skull, the proportion of the spine, the upper and lower limbs, and the pelvis. Some scientists believe that the use of tools made humans less dependent on the front teeth, especially the canine teeth, when feeding and defending against enemies, so the teeth became smaller and the snout shortened.In the process of human origin and evolution, human's intelligence has improved with the enhancement of the ability to transform nature, and the material basis of intelligence and thinking activities - the brain has also gradually increased. Modern apes are based on the original living habits of ancient apes, and are more adapted to the arboreal lifestyle, thus forming its inherent characteristics today. Therefore, erect or semi-erect posture, shortened or lordotic snout, and large or small brain size are the signs of the physical division between humans and apes, and also the signs that reflect the degree of development of human characteristics. 3.Making tools is the exclusive activity of man Only human beings can purposefully make and use labor tools, carry out planned production activities with expected effects, and produce the means of living in the broadest sense for themselves. This is an activity that will cease to exist in nature without human beings. It has the transformation of nature. meaning backlash.That's why the famous philosopher and scientist Benjamin Franklin called man a "tool-making animal". Can ordinary animals make and use tools?Let's take a look at the animals: Bees collect honey, ants feed, and beavers gnaw off branches to build "dams". The "tools" they use are only their own limbs and teeth. On an island in the Pacific Ocean, there lives a small woodpecker called Darwin’s ostrich. It will pick out the thorns of cactus to dig out the bugs hidden in the tree holes, and sometimes break small branches with its beak to remove the branches and leaves.” Processed" into sticks to replace cactus thorns.In its natural state, black apes use their forelimbs and mouths to process grass stalks and twigs, and poke them into termite nests. When termites bite the thin sticks, they pull them out to lick the "caught" termites.Here, the "processing" of "tools" by animals is only carried out by using their own organs. The behavior of "processing" and using "tools" of animals is very different from that of humans making and using tools.The biggest feature of human beings making labor tools is the use of "intermediaries", that is, through tools for making tools. For example, primitive people used a stone to knock another stone to make a stone tool suitable for chopping and smashing. This "chopping tool" is like an axe, which can be used directly as a hunting weapon or to chop. And repair branches and sticks to make wooden weapons or tools.Here, the stone that was originally used to smash stones to make a "chopper" can be called a "stone hammer" and is an intermediary.The finished chopper can be used to make other tools, and it is also an intermediary. They are all tools for making tools, and using them to make tools is not what ordinary animals can do. In addition, in order to adapt to different purposes, people have manufactured various types of tools, especially invented many high-efficiency and complex "combined tools", such as spears, bows and arrows, etc.Moreover, the materials for making tools are also diverse, not only stones, wooden sticks, animal bones, horns, mollusk shells, but also metals and so on.In a word, human making and using tools are complex, frequent and regular activities.The types of "tools" that animals "process" and use are extremely limited, and the activities of using "tools" are also very single, not frequent and regular, but mainly an activity driven by instinct. Even in the best Under the circumstances, there is only a hazy consciousness. Human beings make and use labor tools for production, which is more characteristic, that is, it is a social practice activity, in which various social functions of human beings are developed, such as communication activities through language and developed thinking. Ability makes human beings a "reasonable animal", as the Greek philosopher Socrates said.Moreover, through this kind of social practice, people have also formed various mutual relationships, thus forming an extremely intricate picture in human society.Human beings break away from purely biological unions to form complex social relationships, and human beings become the most social animals.The development of human beings, that is, the development of human society, proceeds according to its inherent laws, which is not found in other animals. Therefore, the activities of animals' "processing" and using "tools" are not real tool processing activities, but mainly the instinct of life, which plays an extremely limited role; while human beings consciously carry out production activities by making and using labor tools , Consciously transform and dominate the natural world, so that the natural world serves its own purposes.This is the truly special animal in nature - man!