Scientists have concrete evidence that Earth is currently experiencing the largest mass extinction in 65 million years. More than 50 species go extinct every day.

It’s called the Holocene Extinction – the Holocene is the current epoch that began at the end of the last ice age, about 10,000 years ago.

From Earth’s fossil record, we know about Six Great Mass Extinctions:

• The Ordovician-Silurian Extinction it occurred about 444 million years ago. At that time, all complex organisms lived in the sea. The most common theory is that the onset of an ice age caused extinction, which wiped out more than 100 families of marine life. Many trilobite families bit the dust during this event.

• The late Devonian extinction it happened 364 million years ago. This event saw a major global extinction of coral reefs and the marine life they supported, as well as other groups of animals and plants. No one is sure what caused it, but scientists speculate that global cooling and various medium-sized asteroid impacts within a few million years of each other may have been to blame.

• The Permo-Triassic Extinction it happened 251 million years ago. The granddaddy of all mass extinctions, this event saw 96% of all marine species and 70% of land vertebrate species kick the evolutionary bucket. The extinction occurred in less than a million years (a very short time in geological terms) and the recovery took 5 million years to resume, and another million years after that to get underway. While not yet considered the smoking gun, this event coincides with the largest known volcanic eruption in history.

• The Triassic-Jurassic Extinction it happened 200 million years ago. Was it caused by climate change, asteroids, or volcanoes? The verdict is unclear. What is clear is that 20% of marine life and many large amphibians were wiped out. At least half of all species on the planet bit the dust. This event occurred over less than a 10,000-year period, just before the supercontinent of Pangea began to dissolve.

• The Cretaceous-Tertiary extinction it happened about 65 million years ago. This event was likely caused, or at least aggravated, by the impact of an asteroid the size of Manhattan. Approximately 16% of marine families and 18% of terrestrial vertebrate families ceased to exist. In North America, more than 50% of plant species may have disappeared. And of course … this is the event that doomed the dinosaurs.

• The Holocene extinction is happening now. Studies of the fossil record show that the normal “background” extinction rate is about one species every four years. The current rate is between 30,000 and 100,000 per year.

You are now witnessing the fastest of the six great mass extinctions. And this extinction, without a doubt, is the result of the growth of the human population. By the end of this century, more than five million species (half of the species on Earth now) are likely to disappear. “It’s not just about species on islands or in rainforests or just charismatic birds or large mammals,” says Stuart Pimm, a conservation biologist researcher at the University of Tennessee. Observe fish, birds, insects, plants, and mammals. “It is everything and it is everywhere … it is a global epidemic of extinctions.”