The earth is a world of life rich in species, the earliest primitive life was born 4 billion years ago. Through continuous evolution and evolution, primitive life has become more and more abundant, and life forms have become more and more complex. Until 500 million years ago, the earth ushered in a life explosion. A large number of complex creatures began to appear, and some amphibians began to gradually evolve into terrestrial creatures, until the Carboniferous period 300 million years ago, primitive terrestrial reptiles appeared.
The emergence of the first reptiles were vertebrates that were fully adapted to life on land in the true sense, and was also a milestone in the history of biological evolution. Although life has ushered in a major explosion in 500 million years, nature does not seem to want the evolution and growth of organisms to be too smooth, so from this time to the present, it has also launched five mass extinction events.
The extinction of this large-scale cluster almost brought life to earth to an end. Fortunately, nature did not do too much, but left a ray of life to living things. Every mass extinction will cause at least 80% of species to become extinct, and after the mass extinction, new species will begin to appear. It can be said that the mass extinction event is an alternation of old and new creatures.
Among the five mass extinctions, the most tragic was the third mass extinction, which caused more than 96% of the land to be extinct, and almost ended the era of life on earth. However, this mass extinction has caused tremendous changes in the biological structure. The era of giant insects that once dominated the earth is over, and a dinosaur that has dominated the earth for 160 million years has begun to appear.
Dinosaurs began to appear after the third mass extinction and developed rapidly, followed by the fourth mass extinction. This mass extinction created an opportunity for the rise of dinosaurs. A large number of biological extinctions disappeared, but dinosaurs miraculously Survived this disaster.
After the end of the mass extinction, the dinosaurs without competitors quickly emerged. It took a short time to become the new overlord of the earth, and they continued to multiply and evolve. When the species was at its most numerous, it reached more than 700 species, spread all over the world.
Although dinosaurs rose in the fourth mass extinction, they did not escape the fifth mass extinction. 65 million years ago, an asteroid with a diameter of 10 kilometers hit the earth, and the shock wave generated by the impact triggered a drastic change in the earth’s ecology. Dinosaurs continue to go extinct due to their inability to adapt to the environment.
In many people’s perceptions, all the dinosaurs 65 million years ago disappeared in the mass extinction, and there were no survivors. So is this really the case? We must understand that the most primitive ancestor of mankind was born earlier than dinosaurs like mammals. In the era when dinosaurs dominated, mammals also existed, but they were very small in number and could only struggle to survive.
All mammals have not disappeared in the fifth mass extinction. Will the dinosaurs all over the world become extinct? We must know that in the 160 million years when dinosaurs dominated the world, dinosaurs swept the entire earth. There were dinosaur races in the sky, the earth running, and the water swimming.
Moreover, the evolutionary forms of dinosaurs are also very diverse, reaching more than 700 kinds, almost all over the food chain, and the number is also very large. We can see this from the large number of dinosaur fossils discovered by modern scientists all over the world. The distribution of dinosaurs at that time was very large.
The dinosaur family 65 million years ago was very prosperous, and a large number of dinosaur fossils can prove their former scenery. For a species all over the world, can a mass extinction event wipe them all out? I am afraid it is very difficult. If the dinosaurs all over the world were extinct at that time, then the ecology may be serious and very terrible. I am afraid that other life will not survive, and the earth will completely become an inanimate planet.
But in fact, the fifth mass extinction only wiped out about 80% of the living things, and the situation was far less serious than the third and fourth time. Since it is not a final mass extinction event, it is unlikely that all the dinosaurs will be extinct. There is a high probability that some of them will survive, and then they will become a new species after a long period of evolutionary evolution.
Why can dinosaurs rise in the fourth mass extinction, but cannot escape the fifth mass extinction? In fact, this issue is not complicated. The fifth mass extinction was caused by an asteroid hitting the earth. The huge shock wave created a global volcanic eruption, which produced a large amount of dust and poisonous gas.
The dust covered the sky and blocked the sunlight for a hundred years. We all know that the photosynthesis of plants is inseparable from sunlight. Without sufficient sunlight, plants will die in large numbers, and plants can release oxygen and purify the air. The survival of earth creatures needs oxygen, especially large creatures like dinosaurs. The reason why they can grow so big is because the earth was an oxygen-rich planet at that time, and the oxygen content in the atmosphere was relatively high.
The large number of plant deaths has caused the earth’s oxygen content to drop significantly, and the low-oxygen environment does not have a particularly large impact on mammals. But for large creatures like dinosaurs, that would be fatal. Therefore, the extinction of dinosaurs has a lot to do with the sharp drop in oxygen content. To a large extent, they were suffocated to death. Coupled with the lack of sunlight, the earth has also entered the Little Ice Age, which is not conducive to the survival of dinosaurs.
Large dinosaurs were unable to adapt to this change in the ecological environment, and they all became extinct in the centuries that followed. But there is a class of dinosaurs that they may survive, and that is the small dinosaurs that can fly. We all know that there is a branch of dinosaurs that dominates the sky, and being able to fly naturally has many advantages.
The ecological upheaval caused by the impact of an asteroid on the earth is not that the entire earth has no place to survive. However, these places where they can survive are either very far away, or the terrain is complex and difficult to walk. Land dinosaurs and marine dinosaurs are naturally unable to go, but dinosaurs that can fly are different. They can fly quickly in the sky without obstacles, and can find places where these environments are okay to survive.
And there is another advantage of pterosaurs, that is, they have thick feathers, which can withstand severe cold. In fact, scientists have discovered many dinosaur fossils that as early as 100 million years ago when dinosaurs dominated the earth, some pterosaurs also began to evolve into modern birds. For example, “Chinese Dragon Bird” is a kind of modern bird. The species is very similar to small carnivorous dinosaurs. The fossils of this dinosaur were once considered primitive birds by scientists.
It can be seen that the dinosaurs did not all go extinct in 65 million years. Some of them survived and evolved into birds, dominating the earth’s sky. They are not extinct and can be seen everywhere around us. So are all terrestrial dinosaurs extinct? In fact, scientists do not agree with this.
Scientists have discovered through studying domestic chickens that its genetic bones are also very similar to Tyrannosaurus rex in the dinosaur era. It is possible that the domestic chicken we like to eat now has its ancestor evolved from the evolution of dinosaurs, and it is also the overlord of the dinosaur family. Such a result may be difficult for many people to accept. The former Tyrannosaurus has now become a weak chicken. This is the magic of the world of life.