Man is not a pig's comrade! Everything is known in comparison (comparative genomics) What do humans and pigs have in common.

The progenitor of domestic pigs is a wild boar, belonging to the genus of artiodactyl non-ruminants. Currently, these farm animals are bred in many countries of the world. But they are most popular in Europe, Russia and the states of East Asia.

Appearance of a pig

From their ancestors, wild boars, domestic pigs do not differ too much. The only thing is that piglets are not usually covered with such thick wool. The anatomy of a pig and a wild boar is almost identical.

Distinctive features of domestic piglets are:

• compact body;
• legs with hooves;
• bristled hairline.

An elongated muzzle ending in a heel, which serves when searching for food to loosen the soil - this, of course, is also one of the main characteristic features of a pig. In the photo below you can see how convenient it is for piglets to use this organ of theirs even when kept at home. It is a cartilaginous movable disc.

The shape of the pig's head can, among other things, determine its appearance. In representatives of meat breeds, it is somewhat elongated. In greasy piglets, this part of the body has a more rounded shape.

Pig Anatomy: Musculoskeletal System

Piglets belong to the class of mammals. The skeleton of these animals is represented by about 200 bones. In this case, the following varieties are distinguished:

• long tubular;
• short;
• long curved;
• lamellar.

The pig skeleton itself consists of several sections:

• skulls;
• body and tail;
• limbs.

The muscular system of the pig is represented by smooth muscles and skeletal muscles. The bones in the body of these animals connect forming joints. In total, pigs have several unpaired and about 200-250 paired muscles.

Digestive and excretory system

Piglets are almost omnivores. And the digestive system of pigs is developed, of course, very well. Its main departments are:

• oral cavity;
• pharynx and esophagus;
• single chamber stomach;
• large and small intestine;
• rectum;
• anus.

For filtering blood and neutralizing harmful substances in pigs, as in any other mammals, the liver is responsible. The stomach in these animals is located in the left hypochondrium, and the pancreas - in the right.

genitourinary system

One of the absolute advantages of pigs as farm animals is their high fertility. The reproductive system of boars is represented by the following organs:

• scrotum and testis;
• duct and spermatic cord;
• urogenital canal;
• penis;
• a special skin fold that covers the penis - the prepuce.

The reproductive system of the female pig is represented by the following organs:

• ovaries;
• fallopian tubes;
• uterus and vagina;
• external organs.

The sexual cycle in a pig can last from 18 to 21 days. These animals bear cubs for 110-118 days. One sow can have up to 20 babies. This is even more than that of rabbits famous for their fertility.

The genitourinary system of the pig is also represented by:

• paired kidneys;
• ureters;
• bladder;
• urethra.

In males, the urethra, among other things, conducts sexual products. In pigs, it opens into the vestibule of the vagina.

Nervous system

Pigs are highly developed animals. It is believed that they are similar in intelligence to dogs. These animals, for example, can be easily taught to carry out various kinds of commands. Like dogs, pigs are able to return from afar to the places where they once lived.

The nervous system of these animals is represented by:

• brain and spinal cord with ganglia;
• nerves.

The brain of these animals has two hemispheres with convolutions and is covered with a bark. Its mass in pigs ranges from 95-145 g. The length of the spinal cord in these animals can be 119-139 cm.

The cardiovascular system

Like other mammals, the central organ of blood circulation in pigs is the heart. It has a conical shape and is divided into right and left halves by a longitudinal partition. Rhythmically contracting, the pig's heart drives blood throughout its body. Each half of the animal heart, in turn, is divided by transverse valves into a ventricle and an atrium.

The blood of pigs consists of plasma and erythrocytes, platelets and leukocytes floating in it. From the heart, it flows through the animal organism through the arteries, and returns to it through the veins. Also, the circulatory system of the pig is represented by capillaries, through the walls of which oxygen enters the tissues.

All kinds of foreign particles and microorganisms are neutralized in the body of these animals in the lymph nodes.

Features of the structure of the skin of pigs

The thickness of the skin of piglets can vary between 1.5-3 mm. In purebred pigs, this figure may even be equal to only 0.6-1 mm. At the same time, the subcutaneous layer in piglets contains a very large amount of fat and can reach a huge thickness.

Mature males have a shield on the sides of the shoulder girdle and chest, consisting of compacted bundles with fatty pads. This formation protects wild boars during fights during the period of sexual hunting.

Rigid bristle hairs on the skin of pigs alternate with soft ones. The density of the hairline in piglets of different breeds may vary. In most cases, bare piglets are, of course, bred on farms. But there are also breeds whose representatives are covered with thick hair, about the same as wild boars.

Analyzers, organs of hearing and vision

The circulatory system of the pig is thus very well developed. The same applies to other organs of piglets. For example, the sense of smell of pigs is simply excellent.

The organ responsible for the perception of smells in these animals is located in the nasal passage and consists of:

• olfactory epithelium;
• receptor cells;
• nerve endings.

The sense of touch in pigs is carried out by receptors of the musculoskeletal system, mucous membranes and skin. The organs of taste in these animals are papillae located in the oral mucosa. The eyeballs in pigs are connected to the brain by the optic nerve.

The ears of these animals consist of the following sections:

• cochlear part;
• pathways;
• brain centers.

Similarities and differences between pigs and humans

Humans, as everyone knows, belong to the class of primates and are descended from apes. Purely outwardly, a person, of course, most of all resembles this particular animal. The same applies to the structure of internal organs. However, in terms of physiology and anatomy, a person is quite close to a pig.

For example, like humans, piglets are omnivores. It is believed that they were once tamed precisely because of this. Wild boars willingly ate the remains of human food. The only difference between humans and pigs in this regard is that the latter have fewer bitter taste receptors in their mouths. Piglet perceives sweet and bitter in a slightly different way than a person.

As you know, the structure of the pig's heart is not much different from the human heart. Doctors even try to use piglets in this regard as donors for both humans and monkeys. The heart of piglets weighs 320 g, in humans - 300 g.

Very similar to human and pig skin. These animals, like people, can even sunbathe. Similar in structure to humans and pigs as well:

• eyes;
• liver;
• kidneys;
• teeth.

The yellow press sometimes even flashes information that sometimes sows in the United States and China are used to carry human embryos.

What do scientists think

People have been raising piglets for a long time. And the anatomy of pigs is studied, of course, just fine. However, there is no clear answer to the question of why piglets and primates are so similar, unfortunately. In this regard, there are only a few untested hypotheses. For example, some scientists believe that the pig itself once descended from a primate.

There is even confirmation of this incredible hypothesis. On the island of Madagascar, researchers have found fossils of lemurs with a long muzzle with a snout. Like pigs, these animals once tore the ground with their noses in search of food. At the same time, instead of hooves, they had a five-fingered hand, like a person's. Yes, and in the embryos of modern pigs, oddly enough, there is the laying of a five-fingered hand and muzzle, like a primate.

Ancient legends are also a kind of confirmation that piglets were once primates. For example, in one of the legends of the inhabitants of the island of Bot, it is stated that in ancient times the hero Kat made people and pigs according to the same pattern. Later, however, the piglets wanted to have their own differences and began to walk on four legs.

Diseases of humans and pigs

Scientists have noticed that the similarity between humans and pigs is not limited to the anatomical structure of the organs. Almost the same in primates and piglets and diseases. For example, in pigs, as in humans, Alzheimer's disease can be diagnosed in old age. Piglets are also very often obese. Can be observed in these animals and Parkinson's disease. The pig in the photo below suffers from just such a disease.

transgenic animals

The heart and other organs in piglets and humans are similar. However, they are not identical. Experiments on the transplantation of pig organs in humans have ended, unfortunately, in failures due to tissue rejection. To solve this problem, scientists began to breed special transgenic pigs. In order to get such piglets, two human genes are introduced into the embryo and one pig gene is turned off.

Many scientists believe that experiments to breed transgenic pigs in the future may actually help solve the problem of tissue rejection during organ transplants. By the way, there is already evidence for this. For example, in 2011, Russian surgeons successfully transplanted a heart valve from a transgenic pig into a patient.

similarity at the genetic level

The anatomy and physiology of pigs is such that, according to some scientists, they are an accurate biological model of a person. According to the structure of DNA, monkeys are, of course, closest to humans. For example, the differences in human and chimpanzee genes are only 1-2%.

But pigs in terms of DNA structure are quite close to humans. The similarity between human and pig DNA is, of course, not so great. However, scientists have found that in humans and piglets, some types of proteins are very similar in composition. That is why piglets were once actively used to obtain insulin.

Recently, in the scientific world, such a topic as growing human organs inside piglets has caused a lot of controversy. Purely theoretically, carrying out such procedures is nothing impossible. After all, the human and pig genomes are indeed somewhat similar.

To obtain organs, human stem cells can simply be placed in a sow's egg. As a result, a hybrid will develop, from which in the future not a full-fledged organism will grow, but only one organ. It can be, for example, the heart or spleen.

Of course, organs grown inside pigs could save the lives of many people. However, many scientists are opposed to this method. Firstly, conducting such experiments, of course, is inhumane in relation to the pigs themselves. Secondly, it is believed that the cultivation of human organs in pigs could lead to the emergence of new genetically modified pathogens that could kill millions of people.

pig man genome

The blood of pigs is biologically 70% identical to human blood. This made possible a very interesting experiment. The scientists took a pregnant sow and injected the embryos with white human blood containing hereditary information. The animal's pregnancy ended in a successful birth.

In the blood of the newly born piglets, the researchers subsequently found cells containing large sections of both human and porcine chromosomes. This, of course, became a real sensation in the scientific world. Among other things, such cells in the body of piglets were also resistant. That is, they persisted for a long time after birth. Simply put, for the first time, scientists have obtained a stable human-pig genome. Of course, there were few such cells in the body of the test pigs, and the animals were in no way similar to humans. However, the resulting genome contained more than a third of human material.

Other research scientists

Be that as it may, the anatomy of pigs is well studied, and the idea of ​​using these animals as donors looks quite attractive. Most scientists at the same time believe that there is nothing impossible in this. Researchers in this regard already have quite serious developments. For example, scientists managed to find out that nerve cells taken from the body of pigs are capable of putting paralyzed people on their feet.

Very high-quality contact lenses are already made from porcine collagen today. Cartilage cells from piglets' ears are used to grow artificial breasts. Scientists have also created a pig that produces omega-3 fatty acids that are useful for the human heart.

Did Charles Darwin at the end of his life renounce his theory of human evolution? Did ancient people find dinosaurs? Is it true that Russia is the cradle of mankind, and who is the Yeti - is it not one of our ancestors who got lost in the centuries? Although paleoanthropology - the science of human evolution - is experiencing a rapid flowering, the origin of man is still surrounded by many myths. These are anti-evolutionary theories, and legends generated by mass culture, and pseudo-scientific ideas that exist among educated and well-read people. Do you want to know how it was "really"? Alexander Sokolov, editor-in-chief of the portal ANTROPOGENESIS.RU, has collected a whole collection of such myths and checked how well they are.

“But why then are organs transplanted from pigs?!” asks the persevering reader.

First, I must disappoint you: people with pig organs so far exist only in fantastic literature. In reality, in wide practice, the matter does not go beyond the transplantation of a porcine heart valve or skin: it is extremely difficult to overcome the rejection reaction caused in the body by a foreign organ.

True, a pig's liver can be connected to the patient ... temporarily - for an hour and a half. This method is practiced to "unload" the patient's own liver, suffering from liver failure: while the connected organ does its job, the diseased liver rests and recovers. In a short time, the body does not have time to recognize a stranger, so that negative consequences for the patient can be avoided. Similar procedures were carried out in the USSR.

Secondly, I don't know, dear reader, whether you eat pork. But many of your compatriots eat. Ask such a compatriot if he would agree to eat soup from ... chimpanzees. A separate question is how much such a soup would cost.

It's not just about genetics, after all. For mass organ transplantation - and transplant doctors are faced with just such a task - an animal donor is needed:

Well-studied (preferably long-term and widely bred in captivity, without unexpected sores);

Easily breeds in captivity;

Suitable in size;

Cheap;

Experiments on which would not cause violent protests of the world community...

Fact: every year in the world several hundred million pigs go to the slaughter and end up on the table for people. For comparison: the total number of gorillas on the planet does not exceed 100,000 individuals, chimpanzees - about 300,000. So which animal is more promising for the needs of xenotransplantation - a pig or a chimpanzee?

However, experiments on organ transplants from monkeys have also been carried out.

Back in the 1900s. Friedenthal performed a successful blood transfusion on a human chimpanzee. And in 1931, J. Troisier conducted a series of experiments on blood transfusion in the opposite direction - from chimpanzees to people, without any negative consequences.

In 1920–30 in France transplantation of tissues of the gonads of monkeys to men, in an effort to achieve the effect of rejuvenation, was carried out by Sergei Abramovich Voronov, the prototype of Professor Preobrazhensky from The Heart of a Dog. Voronov carried out several hundred such operations.

Not certainly in that way! This statement was relevant even several decades ago. Then it was believed that the closest relative of man is anthropoid. This was confirmed by the so-called scale of ingenuity among animals. According to this scale, great apes were the closest. However, a number of experiments and experiments carried out at the present time, all move away from close relationship with man.

According to the theory of evolution, Homo sapiens is an underdeveloped ape that has one less chromosome than, for example, a chimpanzee, but has a similar structure of the skull and forelimbs. Currently, Charles Darwin's theory of the origin of man from apes is not confirmed, which allows the world's scientific minds to look for more and more new "relatives" of man.

Human resemblance to a dolphin

Researchers who studied the brain found that the encephalogram of bottlenose dolphins brings them closer to humans. The fact is that the brain of this species of dolphins is as similar as possible to the human one. The gray matter in these animals is slightly larger than in humans, and also contains more convolutions. According to the research of the Swiss professor A. Portman, the mental features of the dolphin took an honorable second place after the man (the third place among elephants, and the fourth place among monkeys).

What unites a person with pigs?

The anatomical structure of pigs allows us to call them the closest relatives of humans. The fact is that the embryo of this mammalian animal has a bookmark of a five-fingered limb and a muzzle that is very reminiscent of a human face. Piglet on a pig's muzzle and hooves on legs develop immediately before childbirth. In addition, already born pigs have the maximum physiology with humans. That is why pig organs (liver, kidneys, heart, spleen) are used in surgery for human transplantation.

Similarities between humans and rats

These rodents also amazingly copy a person at the anatomical level, but not as much as pigs. Rats have the same blood composition and tissue structure as humans. Curiously, these rodents are the only animals in the world that (like humans) have abstract thinking. Rats can make simple inferences, which allows them to be so tenacious. In addition, if a rat is enlarged to human size, and then the skeleton is straightened, one can see that the joints of humans and rats have the same anatomical structure, and the bones have an equal number of fragments.

Scientists have proven that pigs are much closer to us than monkeys. Some pig organs can be transplanted into humans. Why is it so, and not vice versa?

Whether we like it or not, we all have a lot in common with pigs. We are omnivorous mammals who gain weight easily and are susceptible to influenza. The very fact that pigs and humans are mammals means that we share some genes, which shows the similarity between human and pig DNA.

Scientists refer to the results of studies, according to which the DNA of a pig and a person are 98 percent similar, but in this state of affairs, many are misled, believing that a person is 98% a pig. The amount of genetic material we share with other species depends on what you're comparing.

All living organisms have genetic information encoded in deoxyribonucleic acid (DNA) divided into parts called genes. Information is transmitted from genes by a chemical called ribonucleic acid (RNA). Some RNA is translated into chains of amino acids that make up proteins, the building blocks of every living cell.
Scientists have discovered about 20,000 mammalian genes that code for proteins with similar basic functions. So if you compare some of the coding proteins in our DNA, you will find that we have a lot in common with a lot of mammals.

Pedigree of mammals based on molecular genetic data. It can be seen that the pig is farther from the person than the mouse, rabbit and porcupine.

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It is not so easy to transplant an animal organ into a human. The transplanted organ must match the recipient's age, physique and weight, genetic compatibility is required. Even a human donor is selected very carefully, what to say about a creature of another species.

However, the needs of medical practice dictate their own terms. It would be logical to assume that the organ donor would be the creature closest to humans - a chimpanzee, but transplantologists turned their eyes to ... a pig. People far from science even hurried to question Darwin's theory as a whole in connection with this.

Xenotransplantation: myths and reality

Speculation about the mass transplantation of pig organs to humans is greatly exaggerated. To date, medicine has not gone beyond the transplantation of mechanically functional tissues - heart valves, cartilage and tendons. Tissues before transplantation are treated with special chemicals and ultrasound to destroy antigens and avoid rejection of these tissues by the recipient's body. Even such transplants are very easy to damage during processing, making them unviable, what can we say about more complex formations - the heart, kidney or liver. Therefore, we are not yet talking about the transplantation of whole organs of a pig to a person.

Certain hopes are pinned on the creation of genetically modified pigs. If pig cells are forced to synthesize human glycoproteins on their surface by changing the genome, the human immune system will not perceive such organs as something alien. But this method is still at the stage of laboratory research, it is still far from mass application in medical practice.

Advantages of a pig as a donor

The choice of a pig as a possible organ donor is not at all explained by the genetic proximity of this animal to humans. The most genetically close animal still remains a chimpanzee. But the number of these monkeys in the world is measured in tens of thousands, which is clearly not enough for mass use. Pigs are slaughtered by the millions every year.

As for tissue compatibility, there are animals closer to humans - mice, but they do not fit in size, and pigs in this regard are quite comparable to humans.

People have been breeding pigs for a long time, these animals are well studied. It is unlikely that they will "present" some unknown terrible disease that can be contracted during transplantation. Pigs breed well and grow quickly, and their breeding and maintenance is relatively cheap.

All this makes them prefer pigs to monkeys, the use of which would turn organ transplants - already far from cheap - into a service available only to billionaires.