Eve and No Adam

Copyright (c) 2000 by Mike Resnick.
Reprinted with permission

The late great science fiction grandmaster, Alfred Bester, once wrote a story called "Adam and No Eve". Over the years it has risen to classic status within the field.

Well, Alfie was almost right. The real truth of the matter is that there was Eve and no Adam.

We're talking about the real Adam and Eve here, the most recent common ancestors of the human race, not the Biblical couple who had that little problem with the snake and the apple.

Now, there doesn't seem to be much doubt that Eve, the Big Mama of the race, lived about 150,000 years ago. We've known that for years: we just track mitochondrial DNA, which is passed from a mother to her offspring. But until recently, we could never find a way to pinpoint Adam; then geneticists discovered how to trace the Y chromosome, which occurs only in males.

And now comes the interesting news: Acccording to the Proceedings of the National Academy of Sciences Adam lived only 50,000 years ago.

What does that mean, besides the fact that Eve and a lot of her progeny must have waited an awful long time for Adam to ask them for a date?

Answer: it means a lot more than you think.

Let's digress for a moment and talk about the cheetah. Beautiful animal. Fastest runner in the world. But it's dying out, and not because of poaching. It is having trouble reproducing itself because there is so little genetic variation from one cheetah to another. Which is to say, the DNA of any two cheetahs is almost identical.

And because every human being goes back just 50,000 years to Adam, we're facing much the same problem: our DNA has very little more variation than the cheetah's.

What are the consequences? We're not sure yet. We're not in quite as dire a situation as the cheetah, simply because there are six billion of us and perhaps eight thousand of them.

But the more interesting question is: how the hell did this happen? What killed off Eve's contemporary boyfriend, the guy she knew 100,000 years before Adam hit the scene, and can whatever it was happen again?

And that's where A. E. van Vogt's "nexialism" (also known as "applied wholism"), created for another classic, The Voyage of the Space Beagle comes into play. What I've discussed so far is what DNA scientists know, and indeed is all they can know without looking to another science for a little mutual aid and comfort. In this case, the science of volcanology.

You see, what the DNA result really means is that something came along and wiped out most of the human race a little more than 50,000 years ago. A few of Eve's female descendants survived and kept breeding, but none of her boyfriends did. Every living human being traces to Adam and no farther except through his tail-male pedigree line.

So did a comet hit, the type that wiped out the dinosaurs 65 million years ago?

Nope. Not enough record of other extinctions.

So much for astronomy. And biology. And parts of geology.

But there was one hell of a volcanic explosion, known as the Toba explosion, in or near Sumatra about 70,000 years ago.

How big?

Very big.

There's nothing left to look at in Sumatra, unless you're a volcanologist, but I can give you an example that might help you comprehend the magnitude of the thing.

Kilimanjaro is the tallest mountain in Africa, reaching a snow-capped height of almost 20,000 feet. Nearby is a huge caldara, or collapsed volcano, called the Ngorongoro Crater, a wonderland of African animals that live on its floor. The walls of the Ngorongoro Crater are 7,500 feet high.

But there was a time when Ngorongoro was a taller mountain than Kilimanjaro. Then it flew apart in a huge volcanic explosion and lost more than two-thirds of its height and bulk. That's like losing an entire Mount Mulanje, the tallest mountain in neighboring Malawi, with a few dozen foothills tossed in for good measure.

And the Ngorongoro explosion was nowhere near as powerful as the Toba explosion. The Toba was about 10,000 times as powerful as the Mount St. Helen's blow-up of a few years back.

Back to the DNA guys. Not being nexialists, they're not all buying that the Toba explosion was The Event -- but they agree that there was an Event, and they're pretty much in agreement that humanity was down to a total population of about 10,000 shortly after The Event, whatever it was. And one of those guys -- the Mike Tyson or Mel Gibson of the bunch, take your pick -- is the one we are all related to.

And they're not just saying that you and I are related to him. They took DNA samples of 72 males from 46 separate and distinct population groups -- Causasians, Eskimos, Indians, Orientals, Aborigines, you name it -- and found out that we're all more closely related than any bigot would care to acknowledge.

How can we all be related to one person when there were so many around at the same time? Easy. Let's go to collie pedigrees -- one of my fields of expertise -- to show you how it happens.

Back in 1912 an English collie, Champion Magnet, was imported to America. He won a few shows, lost a lot more, and was soon retired to stud. He didn't get much action from other breeders, and was generally considered a washout as a sire, especially when compared to his more successful contemporaries. He died in total obscurity five years after arriving here.

But two or three of his sons weren't washouts, and ten or twenty of their sons weren't washouts, and suddenly, by 1960, every collie in America could trace its pedigree to the all-but-forgotten Champion Magnet. (I find that comforting. It means the early version of Resnick at least had a chance against the early versions of Tyson and Gibson.)

The question remains: how could one volcanic explosion wipe out most of Earth's humans and leave so much of the rest of life untouched?

They haven't got an answer yet, but they're working on it. The one thing they know is that it happened. (It also goes a long way toward explaining the rise of the Neanderthal, which we know lost out to Homo Sap: he showed up when our numbers were down, and as we started breeding and expanding again, he toddled off to extinction.)

Like I say, they're working on an answer -- and it's pretty important that they find it. There are a lot of other active volcanoes in the world. And I'm getting a little long in tooth for the Adam business.
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