Archean, about 3.3 billion years ago-2.5 billion years ago, was the beginning of life. In the middle Archean period, the earliest organism-prokaryotic cell fungi appeared.
About 2.5 billion years ago-600 million years ago in Proterozoic, life began to flourish. Eukaryotic algae appeared in early Proterozoic, and primitive coelenterates, mollusks and arthropods began to appear in late Proterozoic.
Paleozoic, about 600 million years ago-225 million years ago, was the era of biological explosion. In the Paleozoic Cambrian (about 600 million years ago), invertebrates appeared and algae began to flourish. In Ordovician (about 500 million years ago), vertebrates appeared and marine invertebrates began to flourish; Silurian (about 440 million years ago), fish appeared and plants began to land; In Devonian (about 400 million years ago), amphibians appeared and fish began to flourish; Primitive reptiles appeared in Carboniferous (about 350 million years ago), and amphibians began to flourish. Reptiles similar to mammals appeared in Permian (about 270 million years ago).
The Mesozoic era, about 225 million years ago-70 million years ago, was the era of reptiles. The earliest dinosaurs appeared in Triassic (about 225 million years ago). In Jurassic (about1.800 million years ago), the earliest mammals and birds appeared, gymnosperms flourished and dinosaurs flourished; In Cretaceous (about 65438+35 million years ago), marsupials and placentas appeared, the earliest flowering plants appeared, and dinosaurs ruled the world.
The Cenozoic era from about 70 million years ago to the present is the era of mammals and humans. The Cenozoic Paleocene (about 70 million years ago-3 million years ago) gave birth to advanced mammals. The earliest primates appeared in Eocene (about 60 million years ago); In Oligocene (about 40 million years ago), primates produced monkeys and apes; In Miocene (about 25 million years ago), ancient apes spread in Eurasia; By Pliocene (about 6.5438+0.2 million years ago), apes gradually transformed into humans. The Cenozoic Quaternary (about 3 million years ago to the present) is the era of mankind. In the Quaternary Pleistocene (about 3 million years ago), primitive people began to evolve into modern people. Humans evolved from advanced primate apes.
After becoming a fully formed person, human beings have experienced four stages of development.
First, early apes, also known as homo habilis, appeared between 3 million and 2 million years ago.
Second, the late ape-man, also known as Homo erectus, lived from 654.38+08,000 to 200,000 years ago.
Third, early Homo sapiens, also known as the ancients, lived between 200,000 and 40,000 years ago.
Fourth, the late Homo sapiens, also known as new humans, appeared 40,000 years ago to the present. Late Homo sapiens are modern people.