The Ancient Apocalypse

Finally, a reason to think we'll survive the next apocalypse. Last week, a study that traced the origins of humans through mitochondrial DNA concluded that 70,000 years ago humanity underwent its greatest disaster ever. Africa experienced a massive drought at the time and it devastated our population, leaving perhaps as few as 2,000 people alive on the entire planet. Yet somehow we recovered — a warm thought for all the cold nights we spend dreading nuclear war, the next pandemic, dwindling water and food supplies, and global warming.

Today there are about 6.6 billion people on the planet and climbing fast (remember when we got to 6 billion...nine years ago??). It's hard to read the news and not come up with a laundry list of ways to destroy our civilization, if not all humanity.

So it's nice to know that humanity's a little more rugged than we thought. Here's what researchers from National Geographic Genographic Project had to say on the findings, which was published in the American Journal of Human Genetics:

Previous studies using mitochondrial DNA — which is passed down through mothers — have traced modern humans to a single ''mitochondrial Eve,'' who lived in Africa about 200,000 years ago.

The migrations of humans out of Africa to populate the rest of the world appear to have begun about 60,000 years ago, but little has been known about humans between Eve and that dispersal.

The new study looks at the mitochondrial DNA of the Khoi and San people in South Africa which appear to have diverged from other people between 90,000 and 150,000 years ago.

The researchers led by Doron Behar of Rambam Medical Center in Haifa, Israel and Saharon Rosset of IBM T.J. Watson Research Center in Yorktown Heights, N.Y., and Tel Aviv University concluded that humans separated into small populations prior to the Stone Age, when they came back together and began to increase in numbers and spread to other areas.

Eastern Africa experienced a series of severe droughts between 135,000 and 90,000 years ago and the researchers said this climatological shift may have contributed to the population changes, dividing into small, isolated groups which developed independently.

Paleontologist Meave Leakey, a Genographic adviser, commented: ''Who would have thought that as recently as 70,000 years ago, extremes of climate had reduced our population to such small numbers that we were on the very edge of extinction.''

Source: Associated Press, via PhysOrg