"Joy and pleasure are as real as pain and sorrow and one must learn what they have to teach. . . ." -- Sean Russell, from Gatherer of Clouds

"If you're not having fun, you're not doing it right." -- Helyn D. Goldenberg

"I love you and I'm not afraid." -- Evanescence, "My Last Breath"

“If I hear ‘not allowed’ much oftener,” said Sam, “I’m going to get angry.” -- J.R.R. Tolkien, from Lord of the Rings

Saturday, August 23, 2014

Saturday Science: About That Asteroid

A fairly entertaining video on all (or at least most) of the things that actually caused the extinction of the dinosaurs. Hint: the asteroid was the last straw.


And you may have noticed, that was not the only mass extinction -- there has been a whole series of them, including those known as the Big Five, when over half of all species were wiped out. There's actually an earlier one than the first described in that list, the Great Oxygenation Event, marked by the introduction of free oxygen into the atmosphere, which proved toxic to the anaerobic organisms that were the first life on earth. That one was several billion years ago.

And if you were paying attention to the articles at the links, you will have noted that all of these events involved climate change.

A lot of people are saying that we're heading into the sixth mass extinction. But it's not climate change that's driving it -- it looks like that will be, as it has been in the past, the last straw.

In a new review of scientific literature and analysis of data published in Science, an international team of scientists cautions that the loss and decline of animals is contributing to what appears to be the early days of the planet's sixth mass biological extinction event.

Since 1500, more than 320 terrestrial vertebrates have become extinct. Populations of the remaining species show a 25 percent average decline in abundance. The situation is similarly dire for invertebrate animal life.

The article cites a number of possible reasons, but it all boils down to one thing: the rise of agriculture and the concomitant increase in human population.

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