Animals in ancient times were huge, and if humans went back to ancient times, would humans become gi

No. Because humans are now very mature in evolution, and there is genetic control, humans will not become giants.

Humans will become giants, and in ancient times the temperature was higher than now, and the higher the temperature, the larger the size of the organism.

I think it's possible because in ancient times there was a unique environment in which large animals could survive very well, so people may also develop in a larger and larger direction.

3. Ancient organisms have a large oxygen content in the air and an adequate energy supply, but now they are smaller because of the changes in the energy supply of materials outside the earth. In fact, for us, the reason why the ancient creatures have become smaller is also because the environment on the earth has changed significantly, and the content of oxygen in the air used to be larger, and now the cost in the air has also changed significantly, resulting in many species have also undergone physical changes and adapted to the changing environment.

In general, in ancient times, animals were huge, and it was also because of the support given by the material carriers given by the environment at that time, and now compared to the current external environment, the energy supply on the earth is relatively poor, resulting in the relatively small size of most organisms, which leads to evolution in order to survive.

Because of the abundant resources in ancient times, animals can obtain resources to the greatest extent to develop themselves, so they are huge; Nowadays, there are fewer resource squads, and the animals can't get enough resources, so it's hard to grow big.

Because animals ruled the earth in ancient times, there were no natural predators, and they became smaller mainly to adapt to the environment.

Because the oxygen content on the earth was very high in ancient times, the size of organisms at that time was relatively large, and now the oxygen content is small, and the natural body size has declined.

Because of the decrease in oxygen content and the changes in the biosphere. In many science fiction works, we will see some living primitive creatures, these primitive creatures are generally huge, in fact, in the real world, there really exists a period of history when giant beasts are rampant, in many museums, we can still appreciate the behemoth fossils in the past period. However, the size of the creatures is getting smaller and smaller, so today I will introduce you to why.

About 300 million years from today's Carboniferous period, when the dinosaurs did not rule the earth, the earth is the era of giant insects, the body length of centipedes can even reach several meters long, according to scientists' research at that time, the oxygen content of the earth's air can reach about 30%, so it leads to the growth of many plants tall, and today the earth's air oxygen content has dropped to about 21%, and mammals rule the earth, the body structure of mammals is very precise, so it leads to the size of organisms is getting smaller and smaller.

The mammals are also getting smaller and smaller, and the reason for this situation is the change of the ecological environment, the most famous example is the North American coyote, the North American coyote in prehistoric times has a formidable body size, about 2 meters in length are small, thick skeleton, huge teeth. However, 1,000 years after the end of the Ice Age, with the extinction of large organisms in North America, the coyote's food chain was severely disrupted, and it could only start to hunt small prey, and the change was that the coyote rapidly became smaller in size.

Today's North American coyotes have degraded to the point that there is no difference in size from ordinary wolves, but with the deforestation in the 20th century, the extinction of large predators, coyotes survived with their tenacious survivability, and then began to hunt the sheep brought by people, and now the coyote's physique has rebounded significantly, and it has become a new gray wolf, so the size of the organism changes with the change of the natural environment, the ecological environment in ancient times was suitable for large-sized animals, and today's ecological environment is more suitable for small-sized organisms.

I think it's because there's less food.

The earth has been around for many thousands of years, and although food can still be produced after eating, it cannot be the same as it was in the beginning.

Because the earth's environment is gradually deteriorating, and the atmosphere is getting thinner and thinner, in order to adapt to the environment, animals can only develop in size.

In ancient times, the oxygen content in the air was as high as 30%, but now the oxygen content in the air has dropped to 21%, and most animals were relatively large at that time.

Probably not, because the way humans look like this is the result of a long period of natural selection, and the reminders of ancient humans are not much greater than those of current humans.

If humans really reached the ancient period, they would not have become larger, but might have been poisoned and extinct due to the increased oxygen content.

Humans evolved from apes, on the other hand, if humans go back to ancient times, they have to see how big the monkeys were in ancient times, of course, this is an assumption, maybe it is not impossible to become giants.