Wednesday, 26 February 2014

Everything is Impermanent

Talking about the end of the World, it's not as though it hasn't happened before...................

We had a lively discussion last week at our Sangha meeting about the recent floods here in the UK. We went on to discuss how calls to "Save the planet" are usually focused on saving our own species. The frailty of life on our ever changing planet has faced far worst challenges in the past and has survived even though individual species have not.

There have been what are known as the Big Five mass extinctions, each of which wiped out at least half of all species alive at that time.

In order, they are:-

The Ordovician-Silurian mass extinction

The third largest extinction in Earth's history, the Ordovician-Silurian mass extinction had two peak dying times separated by hundreds of thousands of years. During the Ordovician, most life was in the sea, so it was sea creatures such as trilobites, brachiopods and graptolites that were drastically reduced in number.

The Late Devonian mass extinction

Three quarters of all species on Earth died out in the Late Devonian mass extinction, though it may have been a series of extinctions over several million years, rather than a single event. Life in the shallow seas were the worst affected, and reefs took a hammering, not returning to their former glory until new types of coral evolved over 100 million years later.

This was the big one!
The Permian mass extinction

The Permian mass extinction has been nicknamed The Great Dying, since a staggering 96% of species died out. All life on Earth today is descended from the 4% of species that survived.

The Triassic-Jurassic mass extinction

During the final 18 million years of the Triassic period, there were two or three phases of extinction whose combined effects created the Triassic-Jurassic mass extinction event. Climate change, flood basalt eruptions and an asteroid impact have all been blamed for this loss of life.

The Cretaceous-Tertiary mass extinction

The Cretaceous-Tertiary mass extinction - also known as the K/T extinction - is famed for the death of the dinosaurs. However, many other organisms perished at the end of the Cretaceous including the ammonites, many flowering plants and the last of the pterosaurs.

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