There have been five major mass extinctions in Earth’s history. The first extinction was called the End Ordovician, and occurred over 444 million years ago. This event killed off 86 percent of the Earth’s species and was determined to be caused by a massive freeze that created an ice age.

The next even occurred about 69 million years later, 375 million years ago. This extinction was named the Late Devonian, and killed off about 75 percent of the world’s species.     

One extinction was known as the “Great Dying” and it is the biggest known extinction, killing off a whopping 96 percent of the world’s species. This was the End Permian, and it happened 251 million years ago. This was caused by a couple of natural disasters that leaked dangerous chemicals out of the Earth and into the Earth’s atmosphere. This was by far the worst of all the extinctions, setting life back by 300 million years.

The last two extinctions were pretty similar, with the only real difference being when they occurred. These extinctions are called the End Triassic and the End Cretaceous. They occurred around 200 million years ago and 60 millions years ago, with a total death toll of around 80 percent of Earth’s species in both extinctions.

A sixth extinction is said to be occurring right now, with humans being the number one cause. Our rate of natural resource use and the rapid die-off of species as a result of our actions are the main sources of this extinction. The sixth extinction is expected to kill off more that 70 percent of Earth’s species within a couple of hundred years. Not only could humans be the main reason for other species’ fate from extinction, but we may join them in the sixth extinction if our habits continue.

See here to get more information about the sixth extinction from the YouTube channel “It’s Okay to Be Smart.” It goes into more detail about the problems the Earth will face if we, as humans, do not stop destroying our planet.