life originated in the ocean

The origin of life has always been a subject of research by scientists. Judging from current research results, it is generally believed that life originated in the ocean. Water is an important component of life activities, and the protection of seawater can effectively prevent ultraviolet rays from killing life. The earth was formed about 4.5 billion years ago. About 3.8 billion years ago, when the earth's land was still barren, life began to breed in the roaring ocean - the most primitive cells, whose structures were very similar to modern bacteria. After about 100 million years of evolution, the primitive cells in the ocean gradually evolved into primitive single-cell algae, which are probably the most primitive life. Due to the reproduction of primitive algae and photosynthesis, oxygen and carbon dioxide were produced, preparing conditions for the evolution of life. This primitive single-cell algae has experienced hundreds of millions of years of evolution, producing primitive jellyfish, sponges, trilobites, nautiluses, clams, corals, etc. Fish in the ocean appeared about 400 million years ago. .

life evolution diagram

Due to the attraction of the moon, ocean tides are caused. At high tide, the water laps against the coast; at low tide, large shoals are exposed to the sun. Some organisms that originally lived in the ocean have been trained in the intertidal zone at the junction of sea and land. At the same time, the formation of the ozone layer can prevent ultraviolet damage and make it possible for marine organisms to land. Some organisms survive on land. At the same time, countless primitive lives died in this drastic change. The lives left on land withstood severe tests, adapted to the environment, and gradually developed. About 200 million years ago, reptiles, amphibians, and birds appeared. And all mammals are born on land. Part of them returned to the ocean. About 3 million years ago, highly intelligent humans appeared.

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