ome science fiction, woven from cutting-edge research, takes place not in the future but in the distant past, before the rise of agriculture and civilization. "Cavemen" are often depicted as apelike and mindlessly violent, but the SF of prehistory treats them more gently, as human beings with a world of problems all their own. For example, the works of Jean M. Auel, in which Europe's indigenous Neanderthals (Homo sapiens neanderthalensis) face a slow invasion by more sophisticated Cro-Magnon (Homo sapiens sapiens) peoples. In Auel's imagining, the nomadic Cro-Magnons speak a complex language of abstractions, while the cavern-dwelling Neanderthals—the Clan of the Cave Bear—employ a much simpler language of hand signals, augmenting an even more ancient system of grunts and groans.
Drawing from some of the same sources, two years ago I reported here ("Speaking in Tongues, Baby!") that every human language in existence—the 4,000 spoken today and the thousands more which have gone extinct—are all thought to be descended from a single ancestral language, sometimes known as Ursprach. I even speculated, based on the speech of babies and on patterns identifiable in today's languages, that Ursprach had a simple grammar and a vocabulary of a few hundred words, many of them repeated vowel-constant pairs, like the baby talk "ga-ga, goo-goo, ma-ma."
Well, I'm happy to report that the latest scientific evidence not only bolsters this theory, but adds considerable detail to the drama of human origins. We, of course, can't observe ancient humans directly, but, through a combination of genetic, linguistic and archaeological exploration, we can piece together a surprisingly detailed history of their movements and lifestyle.
The first thread of new evidence stems from the "out of Africa" theory, which examines the genetic evidence to conclude that all humans alive today, everywhere on Earth, are descended from the first modern humans, making their appearance in Africa perhaps 150,000 years ago. Mitochondria are the power plants inside our cells, with their own DNA, separate from the DNA of the cell nucleus which defines what we look like and how we behave. And since mitochondrial DNA is passed down only from the mother's side, its mutations and slow, genetic drift over time can be used to trace the descent of the female side of the human family tree. Similarly, the Y chromosome—found only in men—can be used less precisely to track the male lineage.
And both of these records, along with other genetic markers, tell a similar and very strange story: all human beings alive today are descended from a "mitochondrial Eve" who lived 140,000 years ago and a "Y-chromosome Adam," who lived about 60,000 years ago. Although both were African, the two never met, much less mated, having lived 80,000 years apart! Also, they were by no means the only humans alive at the time. The fact that all modern humans are descended from these two simply reflects the fact that every mother has a mother and every father has a father, in chains stretching back to the very dawn of life on Earth. But not every mother gives birth to daughters, so even if a woman has millions of descendants, her mitochondrial record may end with her. Likewise with men; eventually, a single lineage becomes dominant, and finally universal.
Language may be a family affair
Anyway, Adam and Eve gave birth to 13 distinct genetic "clans." There may have been others in the past which have died out or lost their genetic identity through millennia of intermarriage, but these 13 are still in existence today on the African continent. What's surprising, though, is that there is much greater genetic diversity within Africa than there is outside of it. In fact, all the genetic lineages that originate outside of Africa—from Britain to Australia, from Anchorage to Tierra del Fuego—are descended from the 13th clan alone, specifically from a female ancestor whom archaeologists have named "Lara," who probably also lived about 60,000 years ago.
The most obvious conclusion we can draw from this—bolstered by considerable archaeological and linguistic evidence—is that all non-African humans are descended from a single tribe that crossed the Red Sea from northern Africa to Southeastern Asia shortly after the time of Adam and Lara. It could have been a single breeding pair, or possibly even a single pregnant woman, but it's far likelier to have been a small band of adventurers who swam or waded or perhaps rafted their way across the water, seeking (literally) greener pastures than their own desert climate could sustain. Little did they know they'd become the ancestors of five continents' worth of people!
Moving on to our next discovery, the linguistic evidence points to something even stranger: There are noises found in some African languages that are not found anywhere else in the world. These are the pop and click noises sometimes found in the language groups of Southern and Eastern Africa. The trouble is, some of the languages that contain the sounds are as distantly related to each other as any other languages on Earth, and so are the people who speak them. Genetically and linguistically, they are members of different clans. The sounds are not difficult to make, and they carry well across open terrain (here in America, we still use them to guide horses). Still, people throughout the world agree that the sounds are difficult to fit in around other speech, so the increasing complexity of human language may, over time, have favored their being replaced by easier vowels and consonants in the majority of cases, and never reintroduced.
Moving northward, we find another piece to add to our puzzle on the island of Britain. There, specifically in Wales, we find a family—known to science as the KE family—who harbor a small mutation on a gene called FOXP2, which regulates the growth of certain parts of the nervous system and heart in developing embryos. The strange thing here is that those family members who inherit the mutant gene also inherit a serious speech disorder, which prevents them not only from forming words clearly, but also from forming grammatically coherent sentences. To a lesser extent, it also affects their language comprehension, and causes a small but measurable drop in IQ.
This by itself is not surprising, since one of the areas FOXP2 regulates happens to include the language centers clustered around the ear on the brain's left hemisphere. The KE's brains don't show any gross physical abnormality, but something in their organization is, from our standpoint, not quite right. However, from the standpoint of our closest relatives, the chimpanzees, the altered gene is just fine. In fact, the gene carried by the KE family is not a new mutation at all, but something more like an accidental reversion to the gene's original, apelike form.
Though unfortunate, this situation provides a rare glimpse into the evolutionary origins of human language. By studying the genetic drift of the FOXP2 gene itself, researchers can estimate that the modern version of it—which today is carried by every living human everywhere in the world—arose as an isolated, spontaneous mutation in a single individual, sometime between 200,000 and 100,000 years ago.
Words that speak louder than actions
Here I'll inject a possibly crackpot theory of my own, about the human propensity for rhythm and song. Music's emotional appeal has been linked to the rising and lilting of animal calls; in any mammal we can recognize the sounds of distress, contentment, surprise, etc. Formalized as music, these sounds provide a means of communicating emotional states to others, and even reaching out to project our own emotions onto them. Truly, it's a benign form of mind control, and really does soothe the savage beast, as anyone who's ever sung a sick dog to sleep can tell you. This may, indeed, have been the first technology human beings ever developed: an ability to soothe and even hypnotize other animals.
Those are the puzzle pieces; now let's them together. Picture it with me: It is 1,000 centuries ago. Europe and Asia are already crawling with humans who have escaped from Africa sometime in the past, but their genetic diversity is immense, easily dwarfing the trivial racial differences we too often fret about today. And while these strange humans are skilled at making spears and axes, scrapers and heavy stone hammers, and can also gesture elaborately with their dexterous hands, their ability to modulate their voices—to speak—is only slightly more sophisticated than that of apes. They aren't stupid by any means, but they are very nearly mute, with only a few dozen words in their language and little if any grammar. As a result, their ability to transfer information from one individual to another, from one generation to the next, is quite limited. Indeed, they have difficulty even framing their thoughts symbolically.
Then one day, an African child is born with a strange mutation. It may be a boy or girl—it hardly matters, but for purposes of this story we'll assume the latter, and call her (without sexism, please) "Fox." In any case, unlike any person before her, Fox is born with the gift of gab. She clicks and pops, sings and babytalks this prehuman dialect with unprecedented eloquence, even adding new words and perhaps some simple grammar for clarity's sake. Fox is also unusually cerebral in her thoughts, having mastered the art of abstraction. She can think through complex ideas, and then put them into words which her duller brothers and sisters can understand. As a result, she is wildly popular, not only for her leadership and planning abilities, but also because speaking well is just so damned sexy. A pop star in her own time, she marries the fittest man in the tribe, and bears him several children, each of whom go on to become great leaders and thinkers and orators in their own right.
Within a few generations, the gene is widely disseminated throughout the tribe, and those who haven't got it are discriminated against. Not necessarily out of cruelty, but simply because they can't think or say or do the things that other tribe members take for granted. Mute just isn't sexy anymore. Soon, we find small bands of FOXP2 mutants forming the first tribal nation on Earth: the United Speakers of Ursprach. Their organizational abilities and oral histories are head and shoulders above anything else ever seen on African continent, and in perhaps as little as 10,000 years, through a combination of love and war and economics, they completely displace all the other people, possibly mating them into oblivion or murdering them outright, but more likely just ignoring and outcompeting them, slowly shouldering them aside. And once Africa is conquered from end to end, there is nowhere left to expand to, except perhaps those verdant hills over there across the water. ...
As Jean Auel implies in Clan of the Cave Bear, you do have to feel sorry for the Neanderthals, who were just as nimble as the Cro-Magnons, and were not only physically stronger but also, believe it or not, had slightly larger brains. With stone and bone and wood technology, with music and even the rudiments of religion, they were the masters of their world, lacking only the ability to speak in complete sentences. But against the likes of us—elfin adventurers with quick, clever voices—the poor bastards never stood a chance.
It makes you wonder—doesn't it?—what the world would look like today if the FOXP2 mutation had never occurred, or if it had taken a slightly different form. It also gives us some food for future thought: What happens when the next winning mutation comes along? For all we know, its first carrier—poised to unleash a new wave in human evolution—may be loose in the world already. It might even be you.
Wil McCarthy is a rocket guidance engineer, robot designer, science-fiction author and occasional aquanaut. He has contributed to three interplanetary spacecraft, five communication and weather satellites, a line of landmine-clearing robots and some other "really cool stuff" he can't tell us about. His short writings have graced the pages of Analog, Asimov's, Wired, Nature and other major publications, and his book-length works include the New York Times notable Bloom, The Collapsium and most recently The Wellstone and a related nonfiction book, Hacking Matter.
