There’s a lot of hysteria around right now about extinction. But in truth it’s a natural, perhaps even welcome phenomenon.
Scientific opinion is we are currently living through the Holocene Extinction, Holocene referring to the epoch which began about 12,000 years ago, when the Earth began to warm. There have been about 20 so-called ‘extinction events’ in the past 550 million years, five of which killed off more than 50% of all species.
The Permian-Triassic extinction, about 252 million years ago, killed off 95% of marine species and more than 70% of land species.
Some scientists now argue that mass extinctions are useful – they rid the planet of dominant organisms that restrict biodiversity and competition, and which impede the rate of evolutionary development.
In this view, a mass extinction wipes the slate clean, opening up the chance for new species development.
The cause of the Holocene mass extinction is human impact on the environment.
At least 90% of the organisms that have ever lived are extinct.During 1500-2009 some 875 organisms at least became extinct; probably many more but they went undocumented. Today it’s thought about 140,000 species a year are disappearing.
Picture source: Don Davis via Wikimedia Commons