How many times have life on Earth been destroyed

In geological history, organisms have experienced 5 natural mass extinctions due to geological changes and cataclysms.

The Ordovician is the second epoch of the Paleozoic Era, which began 500 million years ago and lasted for 65 million years. ）

The Devonian is the fourth epoch of the Paleozoic Era, which began about 100 million years ago and ended 100 million years ago, lasting about 50 million years. ）

The Permian is the last epoch of the Paleozoic Era and an important coal-forming period. The Permian is divided into Early Permian, Middle Permian, and Late Permian. The Permian period began about 100 million years ago and extended to 100 million years, a total of 45 million years. ）

The Triassic is the rise of reptiles and gymnosperms, the first of the Mesozoic era. Located between the Permian and Jurassic. It began from 100 million years ago and lasted for about 50 million years. ）

Due to the impact of human activities, species are extinct at a rate 1,000 times faster than natural extinction, and the Earth has entered the sixth mass extinction period.

The Earth has experienced five major mass extinctions, the first of which occurred at the end of the Ordovician period 100 million years ago; the late Devonian period of the second hundred million years ago; The third occurred at the end of the Permian period 100 million years ago; The fourth occurred 200 million years ago in the late Triassic; The last occurred 65 million years ago, at the end of the Cretaceous period.

Some speculate that in the 4.5 billion years of the Earth's history, life has been born several times. Before the formation of our generation of civilizations, it is very likely that there were a number of highly developed civilizations on the earth, but unfortunately they were destroyed by a nuclear war or a major natural disaster. Some people have inferred from archaeological discoveries of 2 billion years old nuclear reactors that there may have been advanced civilizations on Earth 2 billion years ago.

Causes of mass extinctions on Earth:

1. Meteorite impact theory.

Some scientists believe that meteorites or asteroids hit the Earth and caused the mass extinction at the end of the Permian period. If this impact reaches a certain level, it will create a devastating shock wave around the world, causing climate change and the death of life.

2. Supernova ** said.

Astronomers believe that the ozone layer on the Earth's atmospheric surface has been destroyed by the powerful force of gamma rays produced by an aging star hundreds of thousands of light-years, leading to the death of a large number of organisms.

3. Climate change theory.

Some scientists believe that climate change is the main cause of the catastrophe. Because the rocks formed at the end of the Permian period show that the climate cooled in some areas and formed ice sheets. These huge white ice sheets, which emit sunlight back into space, can further lower global temperatures, making it difficult for life on land and at sea to adapt.

Five times. The first was the Ordovician mass extinction at the end of the Ordovician period 100 million years ago; The second was the Devonian mass extinction located in the Devonian period 100 million years ago; The third was the Permian mass extinction located during the Permian period 100 million years ago; The fourth was the Triassic mass extinction, located during the Triassic period 200 million years ago; The fifth was the Cretaceous mass extinction 65 million years ago during the Cretaceous period, which is also called the dinosaur mass extinction.

The Earth has experienced five mass extinction events in its history.

There have been five mass extinction events in the history of the Earth: the first at the end of the Ordovician-early Silurian period, the Persian Paleozoic mass extinction, the third at the end of the Permian and the beginning of the Triassic, the fourth at the end of the Cretaceous, and the fifth from the Neogene to the modern era.

The first extinction occurred about 100 million years ago, when about 85% of all species disappeared. The main cause is climate change, which is affected by sea level decline, glacier development, and extreme weather extremes.

The Persian Paleozoic mass extinction occurred about 100 million years ago, because volcanic activity may have caused the release of greenhouse gases, causing a sharp rise in global temperatures, which caused a huge blow to biological communities, and about 70% of species disappeared.

The third extinction occurred at the end of the Permian and the beginning of the Triassic, about 100 million years ago, and caused the extinction of about 96% of species, including most of the marine flora and fauna and amphibians, mainly due to environmental degradation caused by volcanic activity, climate change and sea level decline.

The fourth extinction occurred at the end of the Cretaceous period, about 65 million years ago, when about 75% of the species disappeared. The main reason is that the global temperature has plummeted due to meteor impacts, which have caused changes in the aftermath of the atmosphere, and may also be caused by large-scale volcanic activity and sea level changes.

The fifth extinction occurred in the neogene-modern period, mainly due to human activities, including over-deforestation, fishing, environmental pollution, climate change and other factors. Another global mass extinction is expected to occur by the end of this century, so people should pay attention to environmental protection and take measures to protect the planet and its creatures.

Significance of mass extinction events

It is a natural succession process in the history of the earth, and each extinction event has shaped the basis of the current earth's bright ecosystem to some extent. Every extinction event is undesirable because it means that millions of lives will be lost, and it also reminds us to better protect our planet and our ecological environment.

There have been five mass extinctions since the beginning of life on Earth, the first of which occurred in the Ordovician period 100 million years ago. Scientists speculate that the main cause of this mass extinction is a sudden change in the environment, which led to the extinction of 85% of species;

The second mass extinction occurred 100 million years ago in the Devonian period, with a huge loss of marine life;

The third mass extinction event occurred at the end of the Permian period 100 million years ago, giving dinosaurs the opportunity to develop and reproduce;

The fourth mass extinction occurred 200 million years ago in the Late Triassic, with significant losses of large numbers of reptiles;

The last mass extinction event was the extinction of the dinosaurs 65 million years ago;

Because the earth has had several drastic changes in the natural environment, or disasters from outside the earth, resulting in serious deterioration of the environment, most of the organisms did not adapt and became extinct.

Trust fate, it's everywhere.