The Sixth Wave of Extinction

The Sixth Wave of Extinction
x
Highlights

“It’s frightening but true: our planet is now amid its sixth mass extinction of plants and animals — the sixth wave of extinctions in the past half-billion years. We’re currently experiencing the worst spate of species die-offs since the loss of the dinosaurs 65 million years ago.

“It’s frightening but true: our planet is now amid its sixth mass extinction of plants and animals — the sixth wave of extinctions in the past half-billion years. We’re currently experiencing the worst spate of species die-offs since the loss of the dinosaurs 65 million years ago.

Rather than a meteorite or large volcanic eruption, the alarming decline of biodiversity leading to the current mass extinction is the result of major human activities," Saket Singh Kaurav, Curator, Nehru Science Centre, Mumbai, on Thursday.

History of life on the Earth witnessed five mass extinctions of species as a result of natural calamities. Currently, biologists are talking more and more often about the sixth wave of extinction provoked in many respects by human beings.

As of today, taxonomists have already described nearly 2 million species, although in fact their number varies, according to various estimates, from 5 to 100 million. But 90 to 99 percent of species ever existing on the planet have already become extinct. The overwhelming majority vanished as a result of the so-called normal or background extinction due to the limited period of biological species existence, which fluctuates from 1 million years with mammals through 11 million years with some marine invertebrates.

Besides the background extinction, the fauna experienced five mass extinctions, as a result of which 50 to 95 per cent of then existing species disappeared within a limited historical period. The first mass extinction occurred 440 million years ago. The fifth one ­ the most renowned extinction ­ hit 65 million years ago.

Researchers are inclined to believe that the Earth came into collision with a large bolide at that time. As a result, sea shoals suffered from tsunami and acid rains, the seabed was covered by enormous amount of organic matter, and only 12 per cent of the then existing species survived on land.

At present, according to numerous specialists' opinion, the sixth - pleistocene - wave of extinction is coming, which has been in many respects provoked by men. That will be the first extinction which did not happed due to natural reasons but as a result of activity of one biological species, whose quantity increases annually by 100 million individuals.

(For more details, visit: http://www.innovations-report.com)

Show Full Article
Print Article
Next Story
More Stories
ADVERTISEMENT
ADVERTISEMENTS