Five times life vanished from Earth and found it’s way back. Evolve or die: This is a universal rule for all Species on the Planet.There were five mass extinction events in the history of Earth. From a Supernova to an asteroid impact, each extinction’s cause was different. Even though these events may seem tragic, we would have never existed without them.
1. ORDOVICIAN – SILURIAN 444 Million years ago.
About 40 minion years ago, life flourished on earth, with the first vertebrates & fish. It was a significant expansion of life on the planet. However, it ended in a disaster. Some terrestrial plants absorbed a lot of carbon dioxide & dissolued the rocks. Because of that minerals are lost to oceans, which led to a massive algal bloom. Algae absorbed even more carbon dioxide, the gas that keeps the Earth warm. Because of all this, Earth went in to the most Significant ice age in history.
2. LATE DEVONIAN 375 Million years ago.
After years of the ice age, life found its way back in a very similar form Plants reached almost 30 m in height but a catastrophe struck once again. According to the latest research, a nearby star explosion could have triggered a mass extinction. A Supernova is such a powerful explosion that it can outshine an entire galaxy for weeks. Due to highly energetic X-rays, UV rays & gamma rays, the ozone layer probably depleted exposing the species on Earth to deadly UV radiation from the Sun.The Late Devonian extinction event wiped 50% of life on the planet. Because of this deadly event, vertebrates did not appear for the next ten million years.
3. PERMIAN – TRIASSIC 252 Million years ago.
Of all the extinction events the permian – Triassic extinction was the deadliest. Also known as the Great Dying, 96% of life was wiped out from the planet. The events most significant cause was an immense volcanic eruption near siberia. The volcano released 14.5 trillion tonnes of carbon leading to global warming. Earth’s temperalure became hellish and the oceans were acidified. so, marine life suffered the most. Because of this catastrophe, marine ecosystem took about 8 million years to recover. Of all the extinction events, this was the only one that wiped out many insect species.
4.TRIASSIC-JURASSIC 201 Million years ago.
After the Great Dying, life took a long time to recover but once it did, it diversified rapidly. Only 50 million years after the Great Dying, the next mass extinction event began. It emptied ecological niches, allowing dinosaurs reign the Earth in the next period. Because of the increased carbon dioxide levels, polar ice melted & marine life was devastated.The loss of 80% of life gave way to dinosaurs, at the Periphery of the ecology.
5. CRETACEOUS- PALEOGENE 66 Million years ago.
The CP extinction event is the most recent one caused by massive asteroid 66 million years ago. The 7.5 mile wide asteroid struck a large water body giving birth to a mega – tsunami. It flung huge volumes of dust, debris and sulfur in to the atmosphere, bringing on severe cooling. The ecosystem began to collapse overnight. All the non avian dinosaurs went extinct. Only a few plants and animals survived. They evolved to forms we know today.
Extinction is the rule Survival is the exception. – CARL SAGAN