Such was the name of a recent program on the Discovery Channel. Without going into program in great detail, the question is just about one theory that one researcher presented (although I might have the numbers off a little):
His contention was that during the Permian extinction, it appears that the massive extinction occurred first on land, for about 40,000 or so years. Then, a second massive extinction occurred in the water, over another 40,000 or so years.
Is that point widely accepted? The researcher came up with this only in the past couple of years.
The earth is deadly. There have been 5 major extinctions. Only one was caused by something other than the the earth itself. Let’s face it…Mother Earth is not a stable creature.
6, even if you don’t count the one we’re in: 1 ) Late Cambrian, 2) Late Ordivician, 3) Late Devonian, 4) End of Permian, 5) Late Triassic, 6) End of Cretaceous.
All species are doomed to extinction eventually. However, hastening that extinction through deliberate effort is hardly “natural”; if someone is hit by a bus, one typically does not claim that he died of “natural causes”.
The causes of the Permian mass extinction remain controversial. Some scientists believe that an impact was involved, although evidence for this is much sparser than for the Cretaceous-Tertiary event.
Impacts have also been suggested as a cause of the Devonian and the Triassic-Jurassic mass extinctions, but the evidence for this is even more tenuous.
How is getting hit by a bus any less “natural” than, say, dying of cancer? Besides being a faster death, of course. If an upstart lion kills the head of its pride, is it displaying unnatural behaviour?
In fact, how can anything humanity does be less natural that a meteor hitting the Earth? At least WE’RE native to this planet.