Speaking of soaring in the blue sky, we may first think of birds, but the most flying ones on the earth are not birds, but insects.
Insects are definitely a bug-like existence in the flying world, but from the appearance, this kind of creature does not seem to be able to fly at all, because their body structure is not aerodynamic at all, and their thin wings and The bulky body makes people feel that they will fall to the ground as soon as they fly, but in fact, insects can not only fly, but also fly very well, especially the dragonfly, the flying champion in the insect world. Its flying ability is unmatched by any flying creature. Yes, dragonflies can fly at a speed of 50 kilometers per hour, and some species can fly continuously for 5,000 kilometers, which is beyond the reach of most birds. What makes other flying creatures even more angry is that insect wings actually grow out of thin air.
There are many kinds of creatures on the earth, and vertebrates are undoubtedly the best among them.
Compared with other organisms, vertebrates have obvious advantages in all aspects, but there is only one thing that bothers the ancestors of vertebrates, and that is flying. If humans want to fly into the sky, they can rely on their own wisdom to achieve this goal, but for the ancestors of vertebrate animals, the only thing they can rely on is evolution. So the forelimbs of some vertebrates began to change, and after a long period of time, they finally evolved into wings. They have wings, but they have lost their forelimbs. However, birds and other vertebrates with wings do not care because they can finally fly freely in the sky. But when they see insects, they use their forelimbs in exchange for The wings suddenly became unscented, because the wings of these guys grew out of thin air.
Insects are undoubtedly one of the most successfully evolved animal species in the world. Among all known animals, insects account for more than 75%.
Insects have a very long history. The oldest known insect fossil is about 358 million years old. However, unlike today's insects, insects in ancient times did not have wings. Why didn’t insects in ancient times have wings? Because they don't need to. Insects first evolved from arthropods in the ocean. Insects at that time can basically be said to be the earliest inhabitants of the earth's land. For them, the land in ancient times had abundant food and no natural enemies, so there was no need to fly. , a down-to-earth crawl is enough.
At the same time, the animals in the ocean were not idle. Soon after, amphibians and reptiles came from the ocean to the land.
Compared with these powerful amphibians and reptiles, insects are too weak. In order to survive, they can only escape. When they couldn't run, the insects began to jump. Some insects found that they could jump farther by flapping their attached wings to absorb sunlight when taking off. Slowly, the attached wings evolved into wings. But this is just a conjecture. Another conjecture is that insect wings do not evolve from a single organ, but are produced by the fusion of multiple organs. This change allows insects to not only have wings, but also retain The original three pairs of legs. If birds and bats see this conjecture, they will definitely feel unfair: Why can they produce one or even two pairs of wings out of thin air, but we have to use their forelimbs in exchange?
The reason why insects do not need to use their forelimbs in exchange for wings is because insects are not as advanced as vertebrates.
The body structure of vertebrates is extremely complex, which makes them only fine-tuned during the process of evolution. For example, an accidental genetic mutation caused the forelimbs of vertebrates to become flat, another accidental genetic mutation changed their finger bones, and the accumulation of countless genetic mutations slowly formed wings. Would it be possible to grow a pair of wings out of thin air through genetic mutation? no.Because the body of a vertebrate is a whole, all structural characteristics are written in genes. If you add something rashly, it will cause the entire body structure to change accordingly, and it will be difficult for this mutant individual to survive. This is the case for some patients with organ ectopia, for example.
Insects are different. The body structure of insects is like a repetitive building block.
If you look closely, you will find that the insect's thorax can be divided into three sections, each section has a pair of legs, and there are three pairs of legs in total. The body structure of each segment of an insect is the same and independent of each other. This means that when a certain segment of the body undergoes structural changes due to genetic mutation, it will not affect the changes in other segments. This makes There are more possibilities for genetic mutations in insects, so insects can add some structures that do not exist on the evolutionary path, or delete some redundant parts, and the success rate of this change is very high, but if it happens to vertebrates Such a huge change is likely to be aborted, so if you want to fly into the sky, you can only turn your forelimbs into wings step by step.
