The earth is a beautiful world of life. Since the early primitive life was born 3.8 billion years ago, it has been through continuous evolution and evolution that the current world of life rich in species has been formed, and at the same time intelligent life humans have been born.
So is the long evolutionary path of life smooth sailing? Of course not. In fact, there have been five mass extinctions in the Earth’s life of nearly 500 million years, and it is believed that there were also large-scale extinctions 500 million years ago. It’s just that the age is too old, and it is difficult for us to find out through the geological structure.
Discovered through the geological structure, the first mass extinction occurred at the end of the Ordovician 440 million years ago, also known as the Ordovician mass extinction. This disaster led to the extinction of approximately 85% of species. The last mass extinction is what we all know. The mass extinction of dinosaurs occurred 65 million years ago. That mass extinction event caused the extinction of more than 80% of the earth’s creatures.
The cause of the mass extinction is closely related to the drastic changes in the earth’s ecology. The first four mass extinction events were caused by drastic changes in the earth’s ecology, and most of the living things were unable to adapt to the changes in the environment and became extinct. Although the fifth mass extinction was brought about by the impact of an asteroid, the asteroid impact ultimately caused a drastic change in the earth’s ecology.
Through statistical research on five mass extinctions in the past 500 million years, scientists have found that mass extinctions occur very regularly, and as long as a long period of time has passed, new mass extinctions will occur. If so, then 65 million years have passed since the fifth mass extinction. From the perspective of the time period, it seems that the sixth mass extinction should happen.
Therefore, scientists have been actively researching and exploring the changes in the earth’s ecology, trying to understand what the current earth’s ecology is like? Has the sixth mass extinction already begun? To predict the occurrence of mass extinction in advance, we need to study some of the characteristics of the environmental upheaval in the last mass extinction.
How to observe these characteristics? Scientists thought of a very special kind of marine life coral. Coral is believed to be familiar to everyone. It is a very common creature on the bottom of the sea. Many people regard coral as a plant. In fact, it is an animal belonging to the phylum Coelenterate. There are more than 7,000 species.
Corals look like branches, with bright and beautiful colors, and many people use them as decorations. So what does coral have to do with the mass extinction? In fact, many people don’t know that coral is a kind of marine life that is very sensitive to the environment. If the ocean environment changes and other organisms, including humans, cannot sense the change, corals will be the first to show some early warning characteristics.
Therefore, scientists study the changes in the earth’s ecology very much to the changes in corals, because the information it occurs is very useful. 65 million years ago, an asteroid hit the earth, causing global earthquakes, tsunamis, volcanoes and large-scale wildfires.
During the period when the asteroid hit the earth, the temperature of the earth first entered an ice age and then rose rapidly. The reason is the global eruption of volcanoes, a large amount of magma and volcanic ash appeared, blocking the sunlight. At this time, the temperature of the earth began to drop, and as the world became cold, some greenhouse gases such as carbon dioxide were also continuously sealed in glaciers and frozen soil.
After the greenhouse gases in the atmosphere are reduced, the earth cools further, and the cooling will cause the greenhouse gases to be further stored. Because the earth entered the ice age and the sunlight was covered by volcanic ash, plants could not enter photosynthesis, so a large number of plants began to die, and a large number of animals could not adapt to the environment and continued to extinct.
The reason for the extinction of dinosaurs was actually starved to death. You must know that dinosaurs were huge in size and needed a lot of food every day. However, a large number of plants died, herbivorous dinosaurs continued to extinct without food, and carnivorous dinosaurs continued to starve to extinction because of lack of food.
Later, as the dust particles in the atmosphere gradually fell on the earth, the sun’s light energy re-entered the earth, causing glaciers and permafrost in some areas to melt, and the frozen greenhouse gases were re-emitted into the atmosphere, which further caused the earth. Warm up. During the entire environmental upheaval, the volcanic ash, dust and gas produced by the impact of asteroids also caused various sulfides to enter the atmosphere, leading to acid rain and ocean acidification.
71% of the earth’s surface area is the ocean. The impact of asteroids on the earth has brought about a drastic ecological change, and the ocean is naturally not immune. Corals, which are ubiquitous in the ocean, are very sensitive organisms, so these ecological changes will show some characteristics in corals, such as: living in deep waters greater than 100 meters below; being distributed worldwide; unlike other organisms Symbiosis; living alone; resistant to bleaching, etc.
The performance characteristics of these corals are actually adjustments made by corals to adapt to new environmental changes. If corals in the ocean now have these characteristics, does that mean that a new mass extinction is about to begin? The answer is obvious. Scientists have studied the corals in the ocean floor and found that the corals now behave very similarly to 66 million years ago, which means that the earth may be experiencing the sixth mass extinction.
If the Earth has indeed entered a new round of mass extinction, the possible cause of all this is very different from the previous five mass extinctions. The first five times were all natural changes in the environment or disasters outside the sky, while the sixth mass extinction was caused by human industrial activities.
We all know that since human beings entered the industrial age, they have been continuously emitting carbon dioxide and other greenhouse gases into the atmosphere. The continuous increase in greenhouse gas content has caused the greenhouse effect to continue to intensify, and the earth’s temperature continues to rise. In recent years, the rising trend of the earth’s temperature is very obvious. When the earth’s temperature rises to a certain level, it will completely collapse the earth’s ecology and cause a huge ecological disaster.
Corals are particularly sensitive to the environment. Due to human disturbance, global warming, and ocean acidification, corals will become extinct in the next few decades, or in several worlds, with more than 30%-50% of coral species. The extinction of corals is like a wake-up call to humans, reminding us that in addition to corals, other creatures on the planet will also face survival tests, including primates.
Scientists estimate that if humans do not protect the existing environment, 75% of living things will face extinction in the next few centuries or even thousands of years. This extinction rate is more than 100 times the normal rate of biological extinction, so scientists believe that the earth may be experiencing the sixth mass extinction.
Of course, many people will say, why can’t I feel the sixth mass extinction? In fact, except for the fifth mass extinction which was relatively sudden and violent due to the impact of asteroids, the duration of the other four mass extinctions was very long, basically over several million years. The entire mass extinction process is slow and gentle, and when the mass extinction is in progress, the most obvious feature is that the environment is getting worse and worse, and the creatures are continuously extinct and disappear.
Compared with our current earth ecology, the environment is getting worse and worse, and organisms will become extinct every year. This is actually very consistent with the characteristics of the mass extinction. Therefore, it is very reasonable for scientists to say that the earth may have entered the sixth mass extinction, but the process may be relatively long.
In the early stages of the mass extinction, we may just feel that the environment is getting worse and worse, and the impact on humans will not be great. But if the mass extinction develops to the middle and late stages, the situation will be completely different. At that time, the ecological collapse is the real end. Of course, at that time, human beings may have been interstellar civilizations and have the ability to colonize outer planets. If the earth cannot survive, we can also go to other planets to survive, and human civilization can still continue.