What is the Evolutionary History of Insects?

Everything is as big as humans and as small as "eyes-free" insects. Insects have appeared from the Devonian period of the Paleozoic (the existence of the earth is divided into 6 generations including apozoic, primordial, protozoic, paleozoic, mesozoic, and cenozoic). 350 million years ago It is nearly 200 million years before birds, so insects can be called old households on Earth.

Overview of the evolutionary history of insects

Right!

Everything is as big as humans and as small as "eyes-free" insects. Insects have appeared from the Devonian period of the Paleozoic (the existence of the earth is divided into 6 generations including apozoic, primordial, protozoic, paleozoic, mesozoic, and cenozoic). 350 million years ago It is nearly 200 million years before birds, so insects can be called old households on Earth.

Chinese name

Overview of the evolutionary history of insects

Existence time

350 million years

Body

Small

Earliest ancestor

Living in the water

Everything is as big as humans and as small as "eyes-free" insects. Insects have appeared from the Devonian period of the Paleozoic (the existence of the earth is divided into 6 generations including apozoic, primordial, protozoic, paleozoic, mesozoic, and cenozoic). 350 million years ago It is nearly 200 million years before birds, so insects can be called old households on Earth.

Although the insect's body is so small, it appeared so early on the earth, and the evidence left behind-the fossils are so rare, but historical scientists still rely on extremely rich imagination and the fossils preserved in the crust. Comparing it with similar living organisms (living fossils) that exist in nature provides clues about the origin of insects that people can believe. The development history of insects on the earth was revealed with the change of all things, the continuation of time, and the continuous evolution and development.

The earliest ancestors of insects lived in the water. They looked like worms and earthworms. The body was divided into many movable links. There were bristles on the front links. They constantly touched the surroundings during exercise and played a sensory role. Below the head and the first link, there are small holes like feeding. This worm-shaped animal with a simple body structure is considered to be the common ancestor of ring animals, leopards and arthropods, and is also the ancestor of insects.

Over time, insect limb function evolved and gradually landed on the land. In order to adapt to terrestrial life, their body structure has undergone tremendous changes. From the original ring-shaped body segments and appendages, it has evolved into a body with three major sections: head, chest and abdomen. This evolution process has gone through a long period of about 200 to 300 million years, and it continues to evolve at a slow pace.

Early insects grew from small to large in appearance. The only difference was that the number of nodes in the body changed, and sexual development changed from immature to mature. At that time, they had no obvious wings for flight on the body, and the original multiple gastropods were not completely degraded. Later, some species of gastropods evolved into organs for jumping; some species still maintained their original postures, such as the Collaptera, Protocera, and Diptera insects, which are now classified as Aptoptera. Over time, around the end of the Devonian period, some insects evolved from wingless to winged.

In the long history of hundreds of millions of years, some species of insects were eliminated by nature during the evolution process because they could not adapt to the drastic changes in the external environment such as glaciers, floods, droughts, and crustal movements. , Gradually adapted to the environment, this is the insect that continues to the present. For example, dragonflies flying in the sky, cockroaches common in warehouses and kitchens, their appearance is no different from the fossil specimens tens of thousands of years ago.

About 290 million years ago, this was the fastest period for insect evolution. During this time, many different shapes of insects have appeared one after another, but most of them belong to the type of incomplete metamorphosis of progressive metamorphosis. In later generations, some insects have developed from infancy to adults, regardless of body shape and development process. There are obvious changes in life, which have to go through four different developmental stages of eggs, larvae, pupae, and adults. Taxa.

Why did the Carboniferous become the hairpin period of insects? This had a very close relationship with the natural environment at the time. Among the many complicated relationships, the relationship with plants is the closest, because most species of insects at that time mainly feed on plants.

During the Carboniferous Period, the forest trees in nature were lush and lush, and the swamps and lakes that provided water for the plants were so dotted, this provided a good opportunity for the herbivorous insects to survive and accelerate their reproduction. However, this superior living environment is not very calm. There is a fierce competition between life and death between plant-eating insects and macro-eating animals, as well as other animals that feed on insects. Not surprisingly, insects are no exception.

In this life-threatening struggle, not the big and fierce species won, but many small, small food and strong reproductive insects, especially plant-eating insects, have gained rapid development opportunities.

The survival and development of insects on the earth has not been smooth sailing, and it has also experienced several large fluctuations. One of the more prominent major devastating disasters occurred 2.
Mesozoic from 300 million to 190 million years ago. At that time, the earth s climate changed suddenly. The vibrant land became barren due to drought. The forest oasis was limited to a small area on the shores of lakes and coastal areas. To feed on survival. During the mutation at this stage, some reptiles that originally lived in the waters changed their living habits and body structure in the water due to the shrinking of the waters, evolved into flying and changed from herbivorous to predatory insects. Archaeopteryx, this caused part of the winged insects flying in the forest and green space to lose the airspace for survival. However, there are also very adaptable insect species that still rely on their own advantages to stubbornly continue their own populations.

It is particularly worth mentioning that during this period (about 130 million to 65 million years ago in the Cretaceous), the formation of modern plant communities on the earth, especially the increase in the species of flowering plants, and the variety of insects that live on nectar Species (such as Lepidoptera) and predatory insects (Insects such as Mantis) are increasing day by day; with the prosperity of mammals and bird families, insects such as hairy order, lice order, and flea order relying on ectoparasite It was also born, and this gradually formed a colorful insect world.