Science,English,and math 7th

【An origin and evolution on the intestine】

《The intestine which is the oldest organ on its origin》

The signal is a command of secreting a digestive enzyme around the intestine.

The function on the intestine of which center is the cell like the sensor is the one which we can see in not only the vertebrate animal but in the invertebrate creatures like insects, squid, octopus, in earthworm, in addition in the hydra which is the oldest on its evolution as multicellular organism.

Each of vertebrate animals evolved from the insects separately from the past a long ago. For example, the origin on…

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【An origin and evolution on the intestine】

《The intestine which is the oldest organ on its origin》

…the origin on the eye is different altogether between the vertebrate animals and insects, but as to the intestine, both the vertebrate animals and insects has the same origin.

After the evolution, various digestive organs were born from the intestine. A cell which stored nutrient separated from the intestine and became a primitive liver.

In the jawless fish, a cell which secretes a hormone separated from the intestine. The hormone adjusted sugar contents in the blood. The cell became…

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【An origin and evolution on the intestine】

《The intestine which is the oldest organ on its origin》

The cell became a pancreas in the jawless fish after that. When the jawless fish had its jaw, the front part of the intestine swelled as a place which stored the food for a while. It was the stomach.

Moreover, there is the cell like the sensor in the intestine of the hydra, and a nerve cell received the information with the cell like the sensor and issued a command other organs around it.

As to some kinds of hydra, the nerve cell crowds together on the entrance of the intestine as if it were…

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【Origin and evolution on the intestine】

《The intestine which is the oldest organ on its origin》

As to some kinds of hydra, the nerve cell crowds together on the entrance of the intestine as if it were a towel worn as a headband. The nerve cell clusters together around the mouth of the intestine, so the professor framed a hypothesis like the next.

Gathering on the nerve cell which is made up on the entrance of the intestine is thought to be an original form on the brain of the vertebrate animals or insects. As a result, we can say the brain is born from the intestine.

The whole body of the…

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【Origin and evolution on the intestine】

《The intestine which is the oldest organ on its origin》

The whole body of the hydra is a thing like the intestine. Its structure is simple as if a tube had feelers. It seems to be a plant at first sight, but it eats a living crustacean 甲殻類. It has been thought a creature linking the vertebrate animals was born from the creature which has the simple structure like the hydra.

As to a lamprey ヤツメウナギ belong to the jawless fish, cells which secrete insulin gathers on the epithelium and is separated. It’s the primitive pancreas. The insulin is a hormone…

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【Origin and evolution on the intestine】

《The intestine which is the oldest organ on its origin》

The insulin is a hormone which decreases sugar content in the blood. Though I expressed the cell which secretes the insulin gathers on the epithelium and separate, but I said the content of the book as it was, so I’m not sure of its real shape. I’m sorry for it.

As fishes have a jaw and can swallow a big prey, the front part of the intestine swells, and a stomach developed as storehouse for foods for a while.

When our ancestors went on land, their excrement has to be stored, so the large…

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【Origin and evolution on the intestine】

《Intestine is the oldest organ on its origin》

…so the big intestine has developed. The primitive intestine like the hydra becomes a digestive organ which has various organs.

Why does the excrement have to be stored? If a predator follows and know the place where its prey is at once, the prey will be easily killed.

【Origin and evolution on the mouth】

《A mouth and anus used to be the same one originally》

A hole which takes in food is indispensable as long as it’s an animal. If thinking like that, the mouth is an organ of which origin…

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【Origin and evolution on the mouth】

《A mouth and anus used to be the same one originally》

…the mouth is the organ of which origin is old like the intestine.

As to the ones like the hydra and jellyfish, a single hole isn’t only the mouth but the anus. When taking in the food and exhausting unnecessary things, the single hole alone is used.

As to our remote ancestor, it is said the mouth and anus used to be the same one, but the primitive intestine made other hole on its opposite side, after that the one hole becomes the mouth and other anus, so the food is conveyed to one direction alone.

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【Origin and evolution on the mouth】

《The mouth and anus used to be the same one originally》

A hint on the evolution is hidden in the process of occurrence on the vertebrate animal.

An fertilized egg grew up and became a round embryo. Its part of the surface sank as if it had got into its inside and formed the original form on the anus. Sinking inside of the body made a hollow. It was the original form on the intestine. A hole was made on the opposite side of the hollow. It was the original form on the mouth.

It has been thought the same thing happened in the process of the evolution.

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【Origin and evolution on the mouth】

《A mouth and anus used to be the same one originally》

By the way, as to the feature on the mouth of the mammals, it can chew.

As to lots of reptiles and amphibians, their nostril was connected to their cell on the mouth, so when the food was in the mouth, they can’t breathe. As a result, they are forced to swallow the food without chewing it, though the amphibian can breathe with its skin.

On the other hand, the mammal can acquire a partition between the mouth and nose by its evolution, so it can breathe when the food is in the mouth. Besides, it can…

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【Origin and evolution on the mouth】

《A mouth and anus used to be the same one originally》

Besides, the mammal can digest the food efficiently by chewing it, but after that, the function of chewing degenerates in the process to the evolution of a person.

When comparing on a profile between a person and an anthropoid 類人猿 like a gorilla, the jaw on the person becomes short. When eating the food, the person learned to use a tool and fire. It’s equal to a digestion outside the body.

In short, the person doesn’t need to have the function of chewing.

The mouths of other mammal are stuck out…

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【Origin and evolution on the mouth】

《A mouth and anus used to be the same one originally》

While mouths of other mammals are stuck out forward, the one of the person is flat, for there is the reason on the evolution according to an illustration on the book.

【Origin and evolution on the backbone】

《The original form on the backbone appeared on the evolution explosively in the Cambrian period》

A person belongs to the vertebrate animal which has the backbone, but how far can we date back the origin on the backbone?

There is the original form on the backbone in the fossil of a creature in...

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【Origin and evolution on the backbone】

《The original form on the backbone appeared on the evolution explosively in the Cambrian period》

There is the original form on the backbone of the fossil of a creature in the Cambrian period. Roughly speaking, the Cambrian period was forty million from a half billion years ago.

The original form on the backbone is called a notochord 脊索. It’s a flexible organization like a bar through the body.

When generating, the notochord appeared and the backbone is formed around the notochord in the vertebrate animals. It has been thought the creature on the…

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【Origin and evolution on the backbone】

《The original form on the backbone appeared on the evolution explosively in the Cambrian period》

It has been thought the creature is the one which remains the form of the remote ancestor to other creatures.

We can see lots of strange creatures which become distinct in the Cambrian period, for example, the one which had five eyes and a long protuberance 突起 like the trunk of an elephant.

It has been thought various kinds of creature were born explosively then, so it is often expressed as a great explosion on the evolution, and the great explosion on…

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【Origin and evolution on the backbone】

《The original form on the backbone appeared explosively in the evolution in the Cambrian period》

…and the great explosion on the evolution has decided the basic design on the vertebrate animals.

The backbone on the fish which is in the water is straight basically, but when going on shore as amphibians, the backbone is curved from around the center due to the gravitation.

As the backbone has a structure like an arch, its internal organs are able to be suspended under the arch efficiently. Or amphibians in the beginning, its head which is ahead of…

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【Origin and evolution on the backbone】

《The original form on the backbone appeared explosively in the evolution of the Cambrian period》

Or in the beginning, the head of amphibian which was ahead of the backbone remained to be close to the ground, but as to more evolved amphibian, its backbone was curved up from around the neck, so it could lift its neck up from the ground.

Those two curves have been received to the mammals as well, moreover one more curve on the backbone around the waist was added to the ancestor of the person. The backbone under the neck is the shape of arch, but it was…

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【Origin and evolution on the backbone】

《The original form on the backbone appeared in the evolution explosively in the Cambrian period》

…but the backbone was curved to opposite direction around the waist. As a result, the weight of the upper half of the body reaches its feet direct. We can stand up straight stably because there has been the secret on the evolution of curving backbone around the waist.

【Origin and evolution on the tooth】

《The tooth used to be the surface on the body originally?》

The skin on a shark is so rough that there is a Japanese phrase, 鮫肌. It’s so rough that it’s …

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【Origin and evolution on the tooth】

《The tooth used to be on the surface of the body originally?》

The skin of the shark is so rough that it’s used for grating wasabi. Why is it so rough? There is its secret in the scale. When investigating the inside structure, it has nature of ivory among the one of enamel. In short, its structure resembles the tooth of a person.

Likewise, the surface of the fossil on the jawless fish is covered with things like small tooth in the Paleozoic era 古生代. The thing like the small tooth is covered with the organization made by enamel, and it’s an origin to...

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【Origin and evolution on the tooth】

《The tooth used to be the surface of the body originally?》

…and it’s origin to our tooth is an influential theory. It means that small teeth around the mouth remains as they were and become our teeth.

The scale of the shark has been thought to be the small teeth on the jawless fish, so it seems our teeth and the scale of the shark are relatives each other.

By the way, as to the teeth on amphibian and lots of reptiles, considering a single individual, each of teeth is cone. Its shape seems to be the same, but some dinosaurs which are ancestor on the…

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【Origin and evolution on the tooth】

《The tooth used to be on the surface of the body originally?》

…but as to some dinosaurs which are ancestors for the mammals, the ones which had some kinds of teeth appeared. 盤竜類 which had a thing like a sail on the back had canine tooth 犬歯 on its fossil.

After that, some shapes of teeth was made on the mammals, for example, the canine tooth of biting food, or a front tooth on the person. The kinds of the tooth became varied in regard to some creatures.

On the other hand, a chewing function on the person degenerated. If comparing the teeth between the…

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【Origin and evolution on the tooth】

《The tooth used to be on the surface of the body originally?》

If comparing the tooth between the person and an anthropoid like a gorilla, the canine tooth doesn’t outstanding on the person. As to the way of lining up the tooth, it was the shape of U in the alphabet on the anthropoid, but it has changed into a parabola because the jaw on the person becomes small.

Some people doesn’t teeth any wisdom tooth which is the third molar tooth in their whole life, and it’s one of example of degenerating biting function.

【Origin and evolution on the nose】

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【Origin and evolution on the nose】

《As the nostrils were pierced and the nose belongs to the respiratory organ》

The nostrils are two, if deciding like that, it’s in the wrong, for our remote ancestor used to have four nostrils. The nose on the person isn’t only an organ which tells a smell, but through which the air passes for breathing.

But as to the nose on a fish which breathing with its gills えら, the nose is used for feeling a smell in the water alone but isn’t used for breathing, and the fish has four nostrils in total, two holes on the one side of the face. The one is water comes in…

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【Origin and evolution on the nose】

《Nostrils were pierced and the nose belongs to the respiratory organ》

The one is water comes in and the other water is out, but coming in and coming out alone, only two is all right, I’m wondering. Why four? I’m not sure of it, and the author didn’t say anything about it.

The nose on the fish is a simple tube which has holes on its both ends, and there is gathering of cell which smells in the tube.

When did the nose belong to the respiratory organ? It started from an amphibian which carried out of going shore? No.

It seems to start from the ones which…

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【Origin and evolution on the nose】

《Nostrils are pierced and the nose belongs to the respiratory organ》

It starts from the ones which belonged to ハイギョ, the fish which breathing with its lung. Then the nostrils were pierced through the part of ceiling, and the nose prepared for belonging to the respiratory organ.

The nostrils used to be four, then where are other two? Other two moved to the eye in the process of evolution. When going on shedding tears, a runny nose is easily caused, for a tube runs from the eye to the nose, and overflowing tears are poured into the nostrils. The tube was…

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【Origin and evolution on the nose】

《The nostrils are pierced and the nose belongs to the respiratory organ》

The tube was diverted from the one on the face of the fish when our ancestor was the fish.

By the way, when the ancestor on the mammals appeared, the leading part on land used to be the dinosaurs. It has been thought the ancestor on the mammal which was like a small mouse was active at night so as to escape from the dinosaurs. As a result, the sense of smell has developed so much.

But after that, the ones which belonged to anthropoid appeared. They lived on the tree in the daytime.

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【Origin and evolution on the nose】

《The nostrils were pierced and the nose belongs to the respiratory organ》

As a result, while the sense of sight is important for the anthropoid, the sense of smell degenerated, and there is a person on the extension of the evolution.

In general, while a muzzle of the mammals sticks out forward so much, the jaw becomes small because the chewing function degenerated on the person. After that the one which is left is the one which protrudes from the face, the nose, which is an original feature on the person.

【Origin and evolution on the eye】

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【Origin and evolution on the eye】

《Evolution on the eye covered with mysterious things》

Is the eye more mysterious than any other organ in the human body, isn’t it?

A crystalline lens of which thickness changes and adjusts the focus. The iris 虹彩 adjusts the amount of light which comes in the eye. The retina 網膜 which is equivalent to the film on a camera. We are forced to admire how the eye elaborate is.

Darwin is famous for the theory of evolution. He wrote the Origin of Species, and said in his book like the next.

I find it hard to think at first sight a complicated organ like the eye…

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【Origin and evolution on the eye】

《Evolution on the eye covering with something mysterious》

I find it hard to think at first sight a complicated organ like the eye evolved step by step by natural selection.

He said like that and treated the evolution on the eye.

How the eye on vertebrate animals has evolved is covered with mysterious things. What kind of process did it go through?

ナメクジウオ which belongs to headless one. Its form is close to the ancestor of vertebrate animal. A photoreceptor cell 視細胞 which detects the light is distributed along around the center of its body, but it…

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【Origin and evolution on the eye】

《Evolution on the eye covering with something mysterious》

…but the ナメクジウオ doesn’t have any complicated organ like the eye.

On the other hand, ヤツメウナギ of jawless fish which has be thought it evolved from the headless one has a structure of perfect eye. There are big distance between ナメクジウオ and ヤツメウナギ. How did the ヤツメウナギ evolve form the ナメクジウオ?

The middle evolution on the eye which fills with the space between two of them has been unclear. It looks as if a perfect eye had appeared in the history of the evolution.

How about the eye except for vertebrate…

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【Origin and evolution on the eye】

《Evolution on the eye covering with something mysterious》

How about the eye except for vertebrate animals? For example, the eye on a squid which is the mollusks 軟体動物 has the crystalline, retina, cornea, and iris, so it looks exactly like the one in the vertebrate animal.

But the relation on the eye between the vertebrate animal and the mollusks is like the one on wing between a bird and a bat. Two of them resemble each other, but each of origin is different.

As to the eye on the mollusks, if comparing the living ones at present, we can know each step on…

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【Origin and evolution on the eye】

《Evolution on the eye covering with something mysterious》

…we can know each step on the evolution.

At first, as to the mollusks, a group of cell on the sense organ lining up on its surface got dented, and the group of cell on the sense organ became a primitive eye. Moreover, when the evolution made progress, the part which got dented became a sunk eye of which shape was a ball, and the crystalline was made in the ball. At last, the cornea was completed, so the perfect structure on the eye like the one on the squid was formed.

As to the eye on vertebrate…

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【Origin and evolution on the eye】

《Evolution on the eye has been covered with something mysterious》

As to the eye on the vertebrate animal, it has been thought it evolved through the same step, but when looking at the generation on each embryo, all the structure on the eye of mollusks is formed from the epidermis 表皮 including the retina.

On the other hand, as to the retina on the vertebrate animal, a part of brain approaches the epidermis and the retina is formed.

It seems to take more time to solve the mystery on the evolution of the vertebrate animal.

Each of the evolution on the…

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【Origin and evolution on the eye】

《Evolution on the eye has been covered with something mysterious》

Each of evolution on the mollusks is different exactly.

As to the eye of カサガイ, its layers of sensor organ is dented softly, but as to the オウムガイ, it becomes a hole, a snail has even the crystalline. Both octopus and squid have a perfect structure on the eye, so they can easily stand comparison with the eye on the vertebrate.

As to the vertebrate animal, there are some layers of nerve cell in front of the photoreceptor cell which receives the light. It means that there are extra films on…

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【Origin and evolution on the eye】

《Evolution on the eye covering with something mysterious》

It resembles that there are extra films on the film of a camera.

On the other hand, as to the mollusks,the light goes into the photoreceptor cell in the retina directly, so it is sometimes said the eye on the mollusks is more rational than the vertebrate animal.

【Origin and evolution on the ear】

《Is the Origin on the ear an organ which detects a current distributing on the surface on the fish?》

The ear is an organ which controls the sense of hearing, the sense of rotation, the sense of balance.

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【Origin and evolution on the ear】

《Is the origin on the ear an organ which detects a current distributing on the surface of the fish?》

A thing of which shape resembles a snail is in charge of the sense of hearing. The semicircular canals 三半規菅 covers the sense of rotation, and the vestibule 前庭 of the ear does the sense of balance. Inner part of the ear including those three parts is called the inner ear.

What’s kind of the thing on the origin of the inner ear?

Though its origin has been unclear at present, there is a theory that a sense organ on the fish at present is its origin.

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【Origin and evolution on the ear】

《Is the origin on the ear an organ which detects a current distributing on the surface of the fish?》

The sense organ is called a lateral line 側線.

It looks that a single or several lines run on the side body of some fishes. They are the lateral lines. They are scales and holes in the scale.

There is a sense organ in the inner part of the hole among the scales, and the sense organ has hair. When water comes in from the hole, the water makes the hair sway. The sway on the hair makes the fish detect a change on current, water pressure...

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【Origin and evolution on the ear】

《Is the origin on the ear an organ which detects a current distributing on the surface of the fish?》

The sway on the hair makes the fish detect both a change on the current and water pressure and sound in the water. It is detected by the lateral line.

The lateral line is useful for finding out a place where a prey is or swimming stably. The lateral line used to be on the head of the early vertebrate animals, and it buried in the body and becomes the inner ear. It’s the theory that the origin of the inner ear is the lateral line.

There is also the cell…

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【Origin and evolution on the ear】

《Is the origin on the ear an organ which detects a current distributing on the surface of the fish?》

There is also the cell having hair in the inner ear of a person. As to the sense of hearing, a sound wave makes the lymphatic fluid sway and the cell having hair detects it. The sound wave is a vibration in the air, and the lymphatic fluid is a body fluid which is filled among tissues.

As to the sense of rotation and the sense of balance, the cell having hair detects a flow on the lymphatic fluid caused by the movement on the body.

The origin on the 耳小骨…

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【Origin and evolution on the ear】

《Is the origin on the ear an organ which detects a current distributing on the surface of the body?》

The origin on the 耳小骨 which connects between the eardrum and the inner ear is interesting as well. The 耳小骨 is made up with three little bones which convey the vibration in the air to the inner ear with which lymphatic fluid is filled efficiently.

In fact, it has been thought the two bones of the 耳小骨 used to be the bones on the joint of the jaw of reptiles, but the two bones learned not to be used, so they were converted into the 耳小骨.

Besides, if dating..

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【Origin and evolution on the ear】

《Is the origin on the ear an organ which detects the current distributing on the surface of the body?》

…if dating back, the bone on the jaw of the vertebrate used to be the one on the gills えら of jawless fish. The 耳小骨 also has a long history.

【Origin and evolution on the lung】

《The lung was born as a bag which sprung out of the intestine》

It is the lung which is indispensable for the vertebrate to go on land, but where is the origin on the lung? Its hint is on a loach どじょう. The loach is out of the surface of the water and…

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【Origin and evolution on the lung】

《The lung was born as a bag which sprung out of the intestine》

…and the loach absorbs the air from the mouth and can do the oxygen with the intestine in which developed the capillary vessel, so even if there isn’t enough oxygen in the water, it can survive there by the intestine respiration. A bubble is sometimes out of the tail of the loach and it’s a proof that the it can do the intestine respiration.

To tell the truth, it has been thought the primitive lung is the front part of the primitive intestine was swollen. We can see the one which is close to…

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【Origin and evolution on the lung】

《The lung was born as a bag which sprung out of the intestine》

We can see the one which is close to the primitive lung in a lungfish.

The lungfish is the one which breathes with the gills, but can do with its lung as well. To my surprise, it estivates 夏眠 in the mud in the dry season.

In some season, the current on the water disappears and the oxygen suddenly decreases on the water. A freshwater fish which used to be in the poor surroundings was suitable for breathing the oxygen with the lung, so the primitive lung was born.

A specialist said like that.

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【Origin and evolution on the lung】

《The lung was born as a bag which sprung out of the intestine》

The difference is breathing with the gills or doing with the lung. It seems to be epoch-making,but to my sorrow it doesn’t ring a bell, for needless to say, neither I’m the specialist nor the fish which used to breathe with the gills.

In general,we the human being including lots of creatures watch a thing with our eyes on the face, but if learning to be able to watch with the top of the head, I’ll be surprised.

It’s the same thing, I’m wondering.

After the fish, a film made up with muscle…

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【Origin and evolution on the lung】

《The lung was born as a bag which was sprung out of the intestine》

After the fish, a film made up with the muscle was formed under the lung in the mammals. It’s the diaphragm 横隔膜. The diaphragm goes up and down in a person and the capacity on the breast skeleton increases and decreases, so the air goes in and comes out from the lung.

By the way, lots of fish have an air bladder ウキブクロ which is a bag including the air, and adjust the buoyancy in the water. It’s the bag which can include the air, so it’s alike the lung.

Does the air bladder have anything to…

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【Origin and evolution on the lung】

《The lung is the one which sprung out of the intestine》

Does the air bladder have anything to do with the lung when evolving?

In fact, it has been thought the air bladder is evolved from the primitive lung. Actually cartilaginous fish 軟骨魚 like a shark of which origin on evolution was old doesn’t have the air bladder.

The fish which acquired the primitive lung returned from the poor surrounding to the deep sea and converted the primitive lung into the air bladder, the specialist said like that.

『The heart has changed its role due to the birth of the lung』

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【The origin and evolution on the lung】

『The heart has changed its role thanks to the birth by the lung』

The heart used to be the pump which sent the oxygen to the grill when being the fish, but when the lung was born, the heart has changed into other kind of pump, which receiving the blood lacking of the oxygen from the whole body and sending it to the lung. The blood which was received in the lung is sent to the whole body by the pump of the heart.

As to the fish, it has a single atrium 心房, and a single ventricle 心室, as to the amphibian, two atriums and the single ventricle, and…

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【Origin and evolution on the lung】

『The heart has changed its role owing to the birth by the lung』

…and the mammals has a wall in the ventricle, so it has two atriums and two ventricles, so the blood on the vein and the one in the artery isn’t mixed. The blood in artery has oxygen and nutrient and was sent to the whole body. On the other hand the blood in vein has waste and carbon dioxide from the whole body.

【Evolution on walking upright and its skeleton】

《A reason why walking upright is possible》

A big event on the evolution has made a person part from the monkeys is walking upright.

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【Evolution on walking upright and its skeleton】

《A reason why walking upright is possible》

A specialist said it has been thought at first walking upright happened, after the degeneration on canine tooth 犬歯, and development on the brain occurred.

Why did the ancestor of a person start walking upright? It has been a big mystery and there are several opinions.

One of the specialists who has studied the fossil on our ancestor said it has been thought walking upright has started so as to carry a fruit to a female as a present from far away. Anyway, walking upright has started in order to…

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【Evolution on walking upright and its skeleton】

《A reason why walking upright is possible》

Anyway walking upright has started in order to having always something in its hand.

As to the skeleton, there is difference between a person who walks upright and other primates 霊長類 in varied ways.

At first, the vertical length on pelvis 骨盤 becomes short, but its width is bigger, and its depth is deepened. The form on the skeleton can make the heavy internal organ support from the lower part. The change on the shape of the backbone is also important.

The structure on joint of the knee is also ….

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【Evolution on walking upright and its skeleton】

《A reason why walking upright is possible》

A structure on the joint of the knee is significant as well.

The joint on the knee is made up with the bone in the thigh. The part where the bone in the thigh and the one in shin touches each other.

Without being dependent on the power on the muscle, a person can stand up straight for a long time, stretching its feet straight on account of the structure on the joint of the knee.

If pushing the back of the knee abruptly on the person who stands up, it loses its balance. What is called 膝カックン.

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