Elizabeth Kolbert on the possible mass extinction of frogs: These amphibians have been around since before there were dinosaurs. But that could soon change. Feb 11, 2014 Interview: Elizabeth Kolbert, Author Of 'The Sixth Extinction' Scientists think an asteroid killed the dinosaurs. In today's extinction, humans are the. Chimie Organique Paul Arnaud Pdf Gratuit Mac there. Free Download Branches Long Arm Rar Programs Free on this page. The Sixth Extinction: An Unnatural History By Elizabeth Kolbert Over the last half a billion years, there have been five mass extinctions, when the diversity of life on earth suddenly and dramatically contracted.

By Ed Stoddard JOHANNESBURG, May 1 (Reuters) - Around 65 million years ago, a massive asteroid or 'bolide' smashed into the Yucatan Peninsula off the coast of southeastern Mexico, sending up a cloud of searing vapor and debris. This effectively killed off the dinosaurs. Some were instantly vaporised, others vanished as vast dust clouds blocked out the sunlight for years. It also ushered in what scientists have dubbed the fifth great extinction event in our planet's history. Many scientists believe a sixth mass die-off of biodiversity is now under way because of the activities of a single species that eventually evolved from the wreckage of the previous one, and managed to colonise the earth - Homo sapiens.