In the late Devonian period, about 377 million years ago, the oxygen content in the atmosphere has reached about 10% of what it is now, and the earth's outer layer has an ozone layer that can block direct radiation from ultraviolet rays, which are extremely beneficial to the terrestrial life of organisms. At this time, in the plant kingdom, certain types of naked ferns gradually evolved into ferns with root, stem and leaf differentiation, and developed in large quantities in the subsequent Carboniferous and early Permian periods, flourishing, and the individuals were often woody trees, constituting a unique fern forest at that time. So this period is also known as the fern age.
In the Carboniferous and Permian periods, which were 350 million to 225 million years old, together with other tall woody ferns such as reeds, scales, and seals, formed the land forests that flourished on the earth at that time. By the end of the Paleozoic Period, due to the movement of the Earth's crust, which caused worldwide climate change, the humid and hot ferns were in decline, and many tall trees were completely extinct. The "fern era" in Earth's history also came to an end. From the Carboniferous to the Permian, the remains of these ferns were piled up in large quantities, then buried in the lake swamps, deteriorated and charred, and over time, a large area of thick coal seams was formed, hence the name Of the Carboniferous in geological history.
Dinosaurs lived about 230 million years ago, and it is generally believed that dinosaurs differentiated from the pseudo-crocodiles in the genus Archaeopteryx. The original dinosaurs were some bipedal carnivorous dinosaurs, by the end of the Triassic period, the evolutionary branch of dinosaurs was basically completed, and by the late Jurassic period, the dinosaur species had developed greatly, and their species and number exceeded those of the pioneers of the Triassic period, and became the real rulers of the earth. Dinosaurs in the Mesozoic Late Cretaceous - Cenozoic early Cenozoic extinction 60-70 million years ago, this ancient fauna that lived on the earth for more than 100 million years mysteriously and mysteriously disappeared all on the earth, dinosaurs ruled the earth for about 165 million years, but the final result was completely disappeared from the earth.
33-24 million years ago, apes emerged from old-world monkeys (narrow-nosed suborder). The earliest ancient apes found in Egypt (30 million years ago) and Egyptian apes (Aegyptopithecus, 26 million to 28 million years ago) already have some traits of apes; later ancient ape fossils and forest apes (23 million to 10 million years ago) have a wide distribution range, and have been found in Asia, Europe, Europe, and Africa. The proto-Consure ape of East Africa (13-12 million years ago) is already an ape, the ancestor of humans and African apes. The above ancient apes are all forest-dwelling animals, walking on all fours, and belong to the ape group of tree climbing. There are two taxa of extant apes, African apes (gorillas, chimpanzees, and humans) and Asian apes (gibbons and orangutans), and there is a clear boundary between these two taxa, and it is clear that the divergence of the two occurred between 12 million and 15 million years ago.
From about 10 million years ago to about 380 or more years ago, there are two kinds of fossil representations of transitional periods. One is rama and the other is australopithecus (many believe to be the ancestor of orangutans, who in the past deviated from the restoration of specimens of jaw fragments and the analysis of teeth). Therefore, there is only relative rationality for the ancient ape to represent the fossil of the transitional period).
Homo erectus: Customarily called "ape man" in China. It lived about 1.7 million years ago or 1.5 million years ago to 200,000 to 300,000 years ago. The geological epoch belongs to the late Early Pleistocene to the Middle Pleistocene. Its brain volume is 775 to 1400 ml.
Early Homo sapiens: Also known as the Ancients or Neanderthals. It lived about 200,000 to 300,000 to 40,000 years ago. The geological epoch belongs to the late Pleistocene.
Late Homo sapiens: Also known as the new man, it appeared 40,000 years ago. Its skull forehead is elevated, the brow crest is almost gone, the jaw is retracted, the chin is obvious, and the physical form is not much different from that of modern humans. The fossils found are distributed on all continents of Asia, Africa, Europe, the United States and Australia, indicating that all continents on the earth are already inhabited at this time except Antarctica.
Today, humans have lived on Earth for hundreds of thousands of years (only 20 or 30 million years from the ape-man count), and the civilization they have built is beyond the reach of the creatures of the past, but this does not allow humans to escape the same fate as other creatures.
It is well known that humans have a total of 23 pairs of chromosomes, and the determining sex is x and y chromosomes, if the two chromosomes are the same (XX), the baby is female; if it is different (XY), then it is male. In this way, the Y chromosome inherits the male lineage, passed from father to son. Both chromosomes were found in animals 300 million years ago, but at that time, the X and Y chromosomes each had more than 1,000 genes. But the male-specific Y chromosome is dying, from 1438 genes at the beginning of its birth to only 45 today. One day in the future, will the human world become the "daughter country" in Journey to the West?
And whether the future human beings will be replaced by other higher intelligent beings, thinking that the civilization established by human beings will no longer exist, thinking about it, my heart is sad and sad!