Why are there no amphibians in evolutionary history?

Let's take it literally. Because the concept of amphibious is not and cannot be defined at the moment.

To understand this, let's first look at what an amphibian is. Amphibians are animals whose larvae live only in water, and adults who live in water or on land.

Many people's understanding of amphibious must have been carried away by words such as amphibious personnel carriers and amphibious stars, thinking that those who can enter the water and go ashore are called amphibious, and those who think that they are on land, water and air are called amphibious.

Let's explain why amphibious is defined in this way, and why there is no amphibious. In fact, amphibious is a relatively low concept, and on the road of evolution, they are the transition stage from water to land. Taxonymously, they belong to terrestrial vertebrates because they already have traits for terrestrial environments, and the aquatic part is derived from fish ancestors.

It is generally accepted that in the late Devonian period, when fish began to move to the continent, it was at that time that amphibians stopped on the path of evolution and were forever inferior to other terrestrial vertebrates. Seeing this, you should understand that there are two reasons for calling it amphibious:

1.It must have two habitats, because its larvae cannot live without water!

2.Because amphibians are an intermediate stage in the evolution of animals. <>

So let's imitate it to define the amphibious [the following are all brain holes]:

1.It must have three habitats, such as being juvenile in the water, growing up on land, and maturing in the sky.

2.It is a transitional creature that evolves from terrestrial to the sky.

The first definition is more difficult to reach. This is because the higher animals that go to land do not skip the process of amphibian development in water, but simply put this process in the body (viviparous) or in the egg (oviparous). The body can provide a safer and more suitable environment, and there is no reason to be in the degraded return water.

Even if such a trait is evolved, there is no reason to eliminate the original trait. Unless it is now that amphibians have evolved directly, skipping the process of terrestrial animals.

Yes! This product, the opossum bug (this large species is commonly known as the field turtle, but it does not bear the opossum but belongs to the opossum bug family with the opossum bug), the demon of the insect world. <>

Since childhood, he has lived near water sources, can swim, dive, crawl, fly, and eat insectsLet's look at the picture. To add, in fact, there is no strict sense of amphibian, let alone evolution into amphibious, because amphibious is only a dependence on aquatic in the process of evolution from aquatic to terrestrial, not an advantage. If there is really the concept of amphibious, it means that there is a dependence on at least two of the environments, then there is no "evolution", and survival will be very passive.

The diet of low-level organisms is extensive, the reproduction rate is high, the amphibious is enough to feed and cope with the scourge of extinction, and there is no need to evolve into a lifelong amphibious to forage for food or migrate to prevent extinction, and there is no evolutionary power.

If judged by the ability to live in three places, land, sea and air, many birds meet the conditions, and a large number of migratory birds can both dive and fly. Nature can go on land. For example, all kinds of diving birds, the diving ability is not low.

I don't think it's a life in the water to be able to swim, but to be able to dive.

But birds, reptiles, mammals, and amniotes are all amniotes. Since it is an amniotic and already has amniotic membranes to protect the development of offspring, there is no need to lay eggs in the water. Known marine crawlers, mammals either go ashore to ovulate or are directly viviparous or ovoviviparous in the water.

If you follow the different positions in the water, land, and sky according to the growth cycle, I don't want to make a big news. <>

But the first thing that comes to mind is this animal.

The origin of amphibians is due to the constant changes in the earth's crust, and their living habits are changed; At first, they were in the water environment, but due to the decline of the crustal change level, they had to be on land, so they had the habit of living on the ground, and their physiology had to evolve due to changes in the environment, thus evolving into amphibians.

With the change of time, amphibians have evolved in nature, and have developed into amphibians based on the principle of survival of the fittest, and can survive underwater and on land, because the earth has evolved in the past hundreds of thousands or even millions of years, the oxygen content and geology on the earth have been constantly changing.

Because with the change of the living environment, animals need to survive in the water and also need to survive on land, so amphibians have evolved aquatic creatures, and they have evolved by crawling to land to survive.

Amphibians are not species that can live both in and out of water. By this standard, most birds are amphibians, capable of diving to catch fish, walking on land, and flying in the air.

Amphibians are the same creatures that have different ways of surviving in juveniles and adults and have different body structures. According to this criterion, amphibians should belong: larvae live in water and breathe with gills; Living on land as an adult, breathing with your lungs; After old age, live in the sky and breathe in other ways.

Currently, the main reason why there are no amphibians is that there are currently no organisms that are able to live forever in the sky, as well as use other means of breathing as their primary means of breathing. Although some animals on the earth can go to the sky and enter water, they still can't live in the air, so there are only amphibians and no amphibians. Personally, I think it has something to do with dimensions, there are only land and water animals on the earth, and there are only amphibians, maybe we still have animals that we haven't found.

In fact, many birds belong to the trifauna, such as mallards, swans, many sea birds...I guess it's an amphibian! Terrestrial animals just swim in the air, which is not fundamentally different from flying, so there are only amphibians, not amphibians.

It means to live, to live. Amphibian larvae live in water, and adults can live on land. Insects and birds, bats can only fly in the air.

Then it is probably bacteria and viruses that are likely to live in the air. However, they belong to microorganisms, taxonomically do not belong to animals, and it is unlikely that they can live both in water and on land, so they cannot be considered amphibians.

The so-called amphibian refers to the larvae of frogs and toads, that is, tadpoles, which live in water and adults live on land, which is the real definition of amphibians, and only if these two conditions are met, can they be called amphibians. Therefore, unless there are animal larvae that survive in the water, semi-adults on land, and adults fly in the air, they can be called so-called amphibians.

It's because there are animals that evolved into amphibians. There are many species on Earth that have evolved over time, and most of them have evolved to adapt to their environment.

I don't know this answer very well, I remember a long time ago I read the Approaching Science column that water has existed since the beginning of the world, and the land was slowly formed by fission, so in order to survive, organisms can only evolve and adapt to water and land to live longer, so amphibians appeared, and it was the environment that created their living habits.

Amphibians evolved from aquatic organisms because they can live both on land and in water, so they are called amphibians.

The main reason is that this kind of animal has special organs that can adapt to two living environments, and it should also be evolved by natural selection.

Amphibians are still evolving.

But evolution doesn't have to create new species right away. Evolution is a very slow process, like continental drift.

We hardly notice any changes in continental drift in our lifetimes, and so is evolution, and if we look back in a million million years, the evolution of amphibians today may be very different.

Usually we humans also divide animals into three categories: terrestrial animals, aquatic animals, and amphibians, and some people may think, since there are amphibians in nature, are there amphibians?

Frogs are a veritable example of this, with both aquatic traits inherited from fish and nascent terrestrial traits, which seem to be a "combination" of aquatic and terrestrial, that is, the amphibians we are talking about. No animal is perfect, amphibians can live on land, but they have very important requirements for the environment, they must live near water, and they cannot stay on land for a long time!

Although the field of the sky is wider and the scope is more vast, we know that most of the animals flying in the sky have no plants or buildings to cover them when they encounter the enemy, they can only bravely face the enemy and defeat them, so that they can have a "way to live", and the most important thing is that many animals almost no longer have to lay eggs in the water, but use oviparity, or viviparity, so that the survival rate of their children will be higher.

Let's imagine that if there are really amphibians, they have experienced aquatic and terrestrial and have to go back to the water to lay eggs when they have babies, and there are also physical problems, so it is impossible for amphibians to fly in the sky all day.

Yes, the monsters in the Pacific Rim are amphibious, although they fly rarely.

That's all there are to the animals on Earth, and all but these two perbians. The rest of the environment is relatively alive, and naturally there will be no other animals, which is quite normal.

Because at most, only amphibious is needed to survive all creatures, and from the perspective of natural selection, there is no need for amphibious.

An amphibian must be able to fly, and if it can fly, it must have feathers. If you can still enter the water, the feathers will be wet, and how can the feathers fly when they are wet? Feathers are also not suitable for walking in the water.

Amphibians refer to animals that can live on land and water, and in the process of evolution, animals will not live in the three realms of land, sea and air at the same time, so they may not have evolved amphibians.

Amphibians are those whose life cycle is in three regions, the hour is in the water, the youth is on land, and the prime of life is in the sky, but no animal can live in the sky all the time.