Undeniable (33 page)

What would things be like, if we were just 1.2 percent different? That is roughly the amount of genetic separation between humans and chimpanzees. What about 0.5 percent different? Well, things would still be different. The other creatures would look almost like us. They might be a little heavyset, but they could walk among us and not look out of place. They would probably behave much as we do. They might be stronger but not quite as sharp before a chessboard or algebra problem.

The 0.5 percent gap apparently describes about a dozen humanlike creatures that lived here on Earth less than four million years ago. We're talking about the hominids, members of our immediate evolutionary family unearthed by paleontologists. You've undoubtedly heard of
Neanderthals
and
Cro-Magnons
. Are you also familiar with the extraordinary finds at these archaeological sites:
Zhoukoudians, Ngandongians, Sangirans,
and
Saint-Césaireans
? The hominids who lived there probably had DNA that was 99.89 percent the same as ours, yet here we are, and they're gone—all of them. Somehow, our ancestors outcompeted them all. Maybe our more recent ancestors were better at mapmaking or storytelling, or pattern recognition in general. Maybe our immediate predecessors had a gene that made them just a little more resistant to a certain type of malaria. Everybody else died out except our direct
Homo sapiens
line.

If my buddy Ivan the gorilla was just 3 percent off from us, and we can build so many more amazing weapons than he could, just think what it would be like to meet aliens whose DNA molecules were 3 percent ahead of ours. We'd have no chance. (Of course they might not have DNA, and the difference might be way more than 3 percent, which hardly makes things look better for us.) In the course of natural selection, a tiny difference in DNA could make all the difference in competing for resources, preparing for a hard winter, or just figuring out escape routes before you needed to get away from the stronger, tougher caveman-style tribe that might be pursuing you.

Modern humans are the result of a burst of evolutionary innovation that took place over the past forty thousand years, probably due in part to a bottleneck. It was punctuated equilibrium in action, somewhere in East Africa. A tribe of our ancestors got cut off from the rest. A favorable set of mutations came through, and we've been passing them along ever since. The humans who passed through that bottleneck were nearly uniform genetically, as typically is the case when you are dealing with a fairly small population. We've been changing faster than ever over the past ten thousand years, and probably up through the past few hundred years. We like to think we're immune to evolution, that we've moved beyond it, but we're still in the thick of it. We just can't quite see the forest for the trees.

The human population continues to grow. When I visited the World's Fair in New York City in 1965, there were 3 billion of us. Today, there are almost 7.2 billion with a b. If there are going to be new gene mutations with new advantages, they'll most likely come from Sub-Saharan Africa, because that's where the most new humans are being produced right now. What will those innovations be exactly? Will the next big innovation in human DNA provide the ability to deal with climate change and high-speed information from all of our devices? Time will tell.

Since all of the other hominids have disappeared, will we be replaced by the next generation of better-built hominids? Is there a
Homo superius
just around the next deep-time corner, waiting to take our place? Let's think about what it would take: If we were to give rise to a new species, something would have to happen to us to create a bottleneck or isolated place for a founder-person and her or his mate to show up and get separated from you and me and our offspring. In the modern world, that is very unlikely. We have airplanes and ships and the Internet.

Circumstances matter; humans are subject to contingency just like any other species. What if we fail to develop defenses to an incoming asteroid? Or if there were an enormous war and all of our intercontinental means of transportation were destroyed? Perhaps then an isolated population of people would live apart from the rest of us for so long that they would no longer be able to successfully interbreed. Just listen to all the dialects we have for speaking English. When human populations are even a little bit separate, they start talking differently. Other bigger changes might happen with more profound separation. Perhaps this could happen somewhere beyond Earth, even, such as in a colony on Mars. Without geographic isolation, I am not sure we can get a new species of hominid, not ever. But that is not the same thing as saying that humans are no longer evolving, because we surely are.

We cannot step away from evolution. Our genomes are always collecting mutations, and we are always making mate selections. Are humans preferentially mating with other humans who are tall? Blonde or not blonde? Sweet, or bitches and jerks? With all of our glamor magazines and self-help books, are we slowly producing offspring that are smarter and better looking? I'll confess that I read the first of the
Fifty Shades of Grey
books. What I got out of it was that an ideal man is a fellow who is young, attractive, and astonishingly wealthy. Who would have guessed? I can't help wondering if that is part of the selection effect that is moving humans steadily further away from Ivan.

Are smart humans choosing other smart humans with whom to have babies, and is that paying off in genetic success? Are they actually producing significantly smarter offspring, who end up making more money and ever so slowly outcompeting other families? Or is intelligence a losing trait, because highly educated couples tend to have smaller families, so when something goes wrong there are fewer siblings left to carry the genes forward? Or since highly educated men and women have babies later in life than those that don't squander their best childbearing years in universities, do the babies of the highly educated enter the world with more trouble in childbirth, and are they prone to more subtle gene troubles that result from later mother and fatherhood? Cue the spooky music.

I am reminded of an old routine by the comedian Steve Martin, who asked: “Do you remember when the world blew up? Remember? We all had to come to this planet on that giant space ark? Remember, the government decided not to tell all the stupid people, because they were afraid that…” He let that sentence taper off, while the audience quickly realized they were being made fun of as “the stupid people” in the joke.

More likely than a future race of hyper-smart people who outcompete the rest of us is a strain of
Homo sapiens
that can beat a disease. Probably the most important evolutionary sieve that any future person is going to have to get through is going to have to do with germs and parasites. Recall that in the Spanish Flu epidemic of 1918–1919, some 50 million people were killed by something far too small to even see, let alone hunt and destroy. The Black Death of the fourteenth century may have killed up to 200 million. You and I are descendants of people who just happen to have the genes to fight off deadly viruses and bacteria.

Those who survive into the future will probably have resistance to certain diseases that none of us have today. There are a lot of other ways that evolutionary change will march on, no matter what. Those that survive may have a higher tolerance for drinking milk. Babies in industrialized societies have access to milk like no one before us. Maybe a genetic tolerance for milk will slowly help more of those babies survive until they have kids of their own. There is evidence that people with both especially high and especially low blood sugar levels have fewer offspring. So subtle changes at least will make their way into the human population's gene pool. It's going on right now.

Then there is a whole other category of possible human futures that are influenced by our own technologies. I give a great many talks or lectures at universities and for general audiences. I enjoy performing, the part where I'm doing the talking and all, but my favorite part of any evening is when audience members come up to microphones and ask me questions. One of the most common themes is what people call “The Singularity.” This is a supposed imminent time (2029, in some versions of the story) when computers will become as sophisticated as human brains. From there, it is proposed, machines will be able to outcompete humans at just about everything. There will be superior car-parking algorithms, disaster-relief coordination, legal briefs, rocket science, great thinking in general. Taking it the next logical step, this artificial intelligence will have to be managed carefully, because after all, any of these future brain machines will outthink and outmaneuver us at every practical turn.

Look, I love thinking in big ways about the future. I love science fiction as much as the next guy. But, I am skeptical that this singularity will be an especially special moment in human history. I say this because somebody has to provide the power for these machines. Somebody has to figuratively (and until 2050 or beyond, still literally, I suspect) shovel the coal. Here in the 2000-teens, we have more mobile phones than we have humans. Even so, only about half of us have access to those devices. There are places in rural Africa and rural China, where people have never made a phone call of any kind. The singularity won't affect them for some time, if at all.

I'm reminded of the 1970 movie
Colossus: The Forbin Project
, which was based on the 1966 novel
Colossus
. In the story, both the U.S. and the Soviet Union use computers to control their astonishingly large arsenals of nuclear weapons. The U.S. machine, called “Colossus,” is in an impenetrable bunker and is powered by its own nuclear reactor (how hard could that be?). Thinking it will help avoid trouble (actually
more
trouble by this point in the story), it's agreed to link the two super machines into one huge machine. As you might imagine, things go wrong in a huge way.

Included in thinking about the singularity is the idea that our information technology will be so sophisticated that we will be able to put human consciousness in some computerlike machine. There are organizations that believe in what they call transhumanism. Humans could then, in a sense, live forever … that is, unless someone pulls the plug. A friend of mine wears an ankle bracelet that explains what to do with her head when she's dead. She wants it frozen in the belief or hope that sometime in the future, we'll be able to connect her dead head to the right machine and bring her brain back to life, or somehow download her stored consciousness. One of the Web sites for her head-storage company brags that they've never had a problem with their cryogenic system, and they've been operating since 1976. It's foolproof, because all they have to do is add liquid nitrogen every three weeks. Wait. Where does one get liquid nitrogen? It's produced using electricity from a power plant. In Michigan, where this company is located, the electricity mostly comes from burning coal. All good for the frozen heads till the grid goes down.

Meanwhile, regular people will be having babies, who may find a great many more interesting things to do than converse with dead people in electric brain machines. Most of those babies will be born in the developing world, which is generally far, far away from these extraordinary future brain tech centers. Of course, as I often remark, I may be wrong. The Colossus machines of the future may be designed to efficiently run entire cities, and they may do it perfectly. It's not hard to imagine sewer systems, solar energy systems, and transportation systems all being directed by a big brain of the future. Nevertheless, I believe sex and nurture will be the main way most of us move our genes into the future even after the singularity machine is debugged in the laboratory.

If you want to reach toward a science fiction future of human evolution—it's fun to speculate, so why not?—a much more reasonable, perhaps inevitable, factor is genetic engineering. Medical scientists are already on the verge of being able to ensure that your baby does not suffer from Huntington's disease or have flat arched feet. Will it be possible to make babies genetically smarter? Or better baseball players? With all of this being done in a petri dish to the eggs and sperm before they're fused? Is that sort of thing ethical? More important, if we make smart people, will they be socially comfortable?

The science fiction stories about superior people produced by genetic engineering almost always end badly. The superior people end up causing too much trouble, generally because they don't fit in with the rest of us. In the real world, these issues will unfold incrementally and, very likely, with a lot of controversy. As a voter and taxpayer, each of us may have some interesting decisions to make about what's allowed in medicine. We may have to address genetically modified people among us who came to be through some future outlawed genetic-engineering technique. What would be the status of illicit human clones? The better informed we all are about all this, the better decisions we'll make.

In contrast, I'm looking out for big changes that come from good old-fashioned Darwinian natural selection. What trait would give a future human baby such an edge that she or he will grow up to produce some amazing new kid that can do something that stands out and will attract a similarly worthy partner with whom to mate? I have heard many women say that they love a guy with a good sense of humor. That one sits well with me for some reason. Will some future guy be so funny, and not so funny looking, that his hilarious sense of humor will win him partners? Will his command of irony be so good that women go wild for him and he mates and reproduces wildly? Legions of present and former stand-up comics hope so. (Many among those legions believe it to their core.) Will it be a guy who can develop such fantastic pectoral muscles, which women find so hot, that he mates and mates?

By the way, what is the sexiest thing about a woman? This is not a trick question. It does not require men to cower fearing a politically incorrect secondary remark or facial gesture. In my opinion, the sexiest thing about a woman is her smile. If the woman doesn't smile, or doesn't smile well, men will not dig her. They will look for other women, who smile well. What's involved in smiling? Good teeth, attentiveness, engaging eyes, and the ability to be happy. Each of these is an apparently inheritable trait. Each is not going to be much affected by sleek computers hooked up to a nest of frozen heads.