NONZERO  THE LOGIC OF HUMAN DESTINY  By  ROBERT WRIGHT
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PART I: A BRIEF HISTORY OF HUMANKIND

PART II: A BRIEF HISTORY OF ORGANIC LIFE

PART III: FROM HERE TO ETERNITY

 

 

 

 

 

 

 

 

 

Chapter Twenty

THE LAST ADAPTATION

As a result of a thousand million years of evolution, the universe is becoming conscious of itself. —Julian Huxley

 

The first hard evidence of culture in the human lineage comes in the form of crude stone tools fashioned more than 2 million years ago. What made our ancestors start using stone tools? The consensus among archaeologists, according to one of them, is that the habitat was becoming "drier, less forested, and/or more dangerous"; these "environmental pressures for survival" forced early hominids to innovate.

Once again we are face-to-face with the dreaded "equilibrium fallacy," the idea that life changes only when jostled by an outside force. When I first heaped scorn on this idea—in chapter 6, while discussing the origins of agriculture—the complaint was that it warped our view of cultural evolution, making the process look more episodic, less persistent, than it is. But we've also seen—just a few pages ago—how a type of equilibrium fallacy can analogously bias one's view of biological evolution. The assumption that a species will change only in response to a changing habitat—and never because of competitive "arms races" among its members—was shown to abet underappreciation of natural selection's complexifying tendencies. Now we have an example of the equilibrum fallacy that is doubly worthy of wrath, because it combines these two malign effects; it entails a warped view of biological and cultural evolution.

For here, more than 2 million years ago, with the first stone tools, our ancestors are in the midst of gene-meme co-evolution. The brain has been growing via biological evolution for some time. But cultural evolution is also in motion. Even before the first stone tools, there were no doubt tools made of less durable stuff, since lost to posterity. And anyway, culture, which today goes well beyond material technology, did so back then, too. Tools aside, inventing or imitating new tricks—for hunting or scavenging or foraging or fighting—would have come in handy. So handy, in fact, that biological evolution would have encouraged this sort of cultural play; to the extent that useful memes paid off in Darwinian terms, aiding genetic proliferation, then natural selection would favor genes for processing memes: genes for innovating, observing, imitating, communicating, learning—genes for culture.

This sort of co-evolution can become a self-feeding process: the brainier that animals get, the better they are at creating and absorbing valuable memes; and the more valuable memes there are floating around, the more Darwinian value there is in apprehending them, so the brainier animals get. In all probability, the first stone-tool-using hominids were already on this co-evolutionary escalator. That would help explain the growth in brain size that had recently distinguished them from the dim-witted Australopithecus afarensis, as well as the ensuing eons of rapid growth—all told, a near-tripling of cranial capacity over 3 million years.

Once you're on this sort of escalator, powered by the positive feedback between the two evolutions, there's no obvious reason to stop. If you don't suffer some grave, species-wide misfortune a meteor collision, say—you're probably headed for big brains and big-time culture. And somewhere along the way, stone tools are pretty sure to get invented. This is not an event that needs a special "explanation." It is just a stage that the escalator passes through (though environmental quirks could of course affect how fast the escalator reaches it).

So, for the destiny-minded observer, the big question isn't: How likely were stone tools? Given the co-evolutionary escalator, stone tools were automatic. The big question, rather, is: How likely was it that the escalator would get cranked up in the first place? My view (surprise!) is: pretty darn likely. Because however dazzling the cultural achievements at the top of the escalator, the various genetically based assets it takes for a species to embark on the escalator in the first place aren't all that exotic.

That isn't to say that our particular ancestors were destined for embarkation. Indeed, our lineage was just flat-out lucky to find itself in possession of the portfolio of key biological assets. But there's a difference between saying it took great luck for you to be the winner and saying it took great luck for there to be a winner. This is the distinction off which lotteries, casinos, and bingo parlors make their money. In the game of evolution, I submit, it was just a matter of time before one species or another raised its hand (or, at least, its grasping appendage) and said, "Bingo."...

[SNIP]

An excerpt from Nonzero: The Logic of Human Destiny, By Robert Wright, published by Pantheon Books. Copyright 2000 by Robert Wright. Other excerpts are available at www.nonzero.org.