Do four legged animals run fast, or do two legged animals run fast?

It's hard to say, for example, a tortoise has 4 legs and a rabbit has 2 legs, but a tortoise is not as fast as a rabbit, and similarly a rabbit has 2 legs and a cheetah has 4 legs, but a rabbit is not as fast as a cheetah. Complete.

Kangaroos are the largest mammal to jump on both hind legs, and jumping is a strange gait for large mammals, but it's not the only way kangaroos walk. Kangaroos don't just jump and move, they also crawl on the balls of their four feet when moving slowly, but one pair of forelimbs moves with one pair of hind limbs rather than alternately.

The fastest four-legged runner is the cheetah.

The cheetah is the fastest animal in the world to run on land, it can reach speeds of up to 115 kilometers per hour. If the human sprint world champion were to race the 100 meters with the cheetah, the cheetah would allow the world champion to run 60 meters first, and it would be the cheetah who would reach the finish line instead of the sprint world champion.

But it should be noted that since the cheetah runs so fast, it is a test for its entire body's respiratory and circulatory systems. When it runs at speeds of more than 115 km/h, its respiratory and circulatory systems are overloaded. Because the cheetah is unable to expel the accumulated heat all at once, it is easy to have prostration symptoms, so the cheetah can only sprint a few hundred meters before it slows down.

Otherwise, it will overheat and collapse. So this kind of running is very dementing, sometimes the cheetah catches the prey, because it just ran too fast, so it can't eat at that time, it has to rest, or gasp. to start eating.

1. Four-legged animals such as: dogs, cats, cows, sheep, horses, pigs, wolves, frogs, crocodiles, rabbits, giant pandas, golden monkeys, Asian elephants, Siberian tigers, clouded leopards, golden leopards, golden cats, black muntjacs, serows, poplar crocodiles, seals, turtles, giraffes, zebras, African lions, American tigers, black leopards, red-chained land-necked kangaroos, emu, golden snub-nosed monkeys, black langurs, hairy crowned deer, etc.

2. There are too many four-legged animals, all mammals (mammals, there are 20 orders of mammals in the world, 4010 species), all turtles (about 257 species of turtles in 12 families), crocodiles (more than 20 species in total), all amphibians (frogs, salamanders, giant salamanders, a total of 5743 species known) are four-legged, and the total number of sheds adds up to tens of thousands.

In our daily life, I believe that many people are very interested in natural science, so there are many children who like to be on TV since childhood** a variety of programs similar to the animal world and explain animals. In the process of growth and development, many friends will have a certain understanding of themselves and all the creatures on the earth, but there are also many friends who have a very strong confusion about the individual form of organisms. So why are there two-legged creatures in the world and four-legged creatures, and why are there no three-legged creatures in the world?

This question is actually very easy to answer, from the point of view of the body structure of animals, if there are three-legged creatures in the world, then it is likely to cause the creatures to encounter a lot of trouble in the process of walking. By looking at the two-legged creature and the four-legged creature, we can find that the two-legged creature is in a relatively balanced and coordinated state during the process of walking, and the four-legged creature will also carry out the left and right sides at the same time in the process of walking, so as to maintain a stable position.

Although the triangle is the most stable figure in mathematics, it does not mean that a three-legged creature can survive the most in the biological world. In fact, in essence, human beings were also four-legged creatures at the beginning, but because in the process of evolution, people used the last two legs more frequently, so people slowly learned to walk upright, so that they changed from four-legged creatures to two-legged creatures. Three-legged creatures will definitely encounter some obstacles in the process of walking, because this will cause the left and right sides to be in a very uncoordinated and unbalanced state, so they will be eliminated by nature.

So that's why there are only two- or four-legged creatures in the world, and no three-legged creatures, because this does not conform to the symmetry of the animal body at all, not only does it look very unsightly, but it will also be very uncoordinated in the process of walking.

I think the first is due to the fact that the genes of the world have been determined, there are only two legs and four legs, and mainly because the genetic elements of the animals in the world are developed according to a principle of symmetry.

The fastest biped on land at the moment is the ostrich.

It's an ostrich, and it only has two toes.

Ostriches, snake vultures are also interesting.

Ostriches are the largest birds and the fastest bipeds.

Two legs: All kinds of birds such as sparrows, swallows, seagulls, red-crowned cranes, chickens, ducks, geese, eagles, crows, peacocks, etc., birds are generally two-legged.

Four-legged: Most mammals such as lions, tigers, leopards, wolves, dogs, cats, rabbits, horses, cows, pigs, rats, sheep, camels, elephants, mammals have many four-legged legs.

Legless: most fish and some molluscs: earthworms, snakes, snails, snails, shellfish, mussels, whales, sharks, dolphins, etc.

1. Two legs.

Kangaroos, crows, swallows, eagles, red-crowned cranes, ostriches, penguins, emus, cranes, American ostriches, kiwis, moas, red-throated loons, limelights, rednecks, short-tailed albatrosses, black-tailed petrels, brown pelicans, blue-footed boobies, common cormorants, African vulture storks, black storks, whale-headed storks.

2. Four legs.

Tigers, lions, leopards, elephants, horses, cows, sheep, mice, dogs, cats, rabbits, pigs, zebras, hippos, wolves, giraffes, tortoises, chameleons, crocodiles, lizards.

Three, no legs.

Python, cobra, mouse snake, five-step snake, pit viper, silver krait, king snake, black snake, long-snouted sea snake, black mamba snake, silver krait, seahorse, yellow eel, carp, crucian carp, sturgeon, grass carp.