The Next Species: The Future of Evolution in the Aftermath of Man (9 page)

Neanderthals hunted in forested areas where they could ambush prey at close range using thrusting spears to bring them down. They relied almost completely on large and medium-size mammals like horses, deer, bison, and wild cattle for food. It was a hard living. Remains of Neanderthal bodies resemble rodeo contestants in that they bear multiple scars and fractures. Neanderthals adapted to live in warmer forested climates, but toward the end of their reign, Europe got colder and ice covered Scandinavian mountains and northern Britain, enclosing them in barren, glacial landscapes. Neanderthals moved into the southernmost forests surrounding the Mediterranean to escape the cold and the spreading open terrain.

Meanwhile,
Homo sapiens
moved up into Europe during a brief interval in the larger cold phase between 58,000 and 28,000 years ago, and adapted well. They were lighter than Neanderthals, needed fewer calories to survive, and were more omnivorous. And they weren’t against an occasional meal of fish or even a vegetable or two. They hunted with lighter stone-tipped spears that could be thrown at a distance. They also used spear throwers (atlatls), which consisted of a shaft with a cup at the end into which the spear fit, giving the hurtler and his spear additional leverage, distance, and velocity. Using a thrower, a human could toss a spear up to 325 feet (100 meters), though it was most effective and mortal at about half that distance.

The end came for Neanderthals during the period when
Homo sapiens
were undergoing their grandest growth—an explosion of culture, symbolic communication, and art. While the communities of modern man grew, Neanderthal communities remained small, and the range of their influence was smaller, too. Neanderthals were lucky to collect stones sixty-two miles (one hundred kilometers) away, while
Homo sapiens
collected stones up to three hundred ten miles (five hundred kilometers) away.

“
Homo Sapiens
had the ability to develop trade at a much greater distance than Neanderthals,” says Rick Potts, director of the Smithsonian’s Human Origins Program. “Our species can get something
five hundred kilometers away, or develop an alliance with someone five hundred kilometers away. In the end, that can really buffer bad times.”

Neanderthals gradually disappeared from Britain, Greece, the Middle East, Russia, and Mongolia. Their last stand may have been in the caves beneath the Rock of Gibraltar. Did the Neanderthals go peacefully, or were they pushed over the evolutionary cliff? Scientists believe that early hunter-gatherer societies were more aggressive than previously judged.

One of the biggest advantages
Homo sapiens
may have had over other hominids was language. Language gave moderns the ability to pass on the lessons of the past. Communication and the ability to remember and utilize a broader range of information allowed for innovation. “And
Homo sapiens
had the ability to accumulate innovation,” says Rick Potts. No other species had demonstrated this before.

The ability to understand language may have actually preceded the ability to talk. Beneficial mutations in the genetics of understanding may have come before mutations in the ability to mouth words. Thus scientists have had luck getting primates, chimpanzees, orangutans, and bonobos to understand language but less luck getting them to talk.

Robert Shumaker, vice president of conservation and life sciences at the Indianapolis Zoo, told me that there have been several studies aimed at getting monkeys and other primates to speak English. Vicky, a chimpanzee raised by scientists in the early 1900s, was trained to vocalize breathy imitations of
“Mama,” “Papa,” “cup,” and “up,” but the efforts were laborious and the lessons soon forgotten. Great apes simply don’t have the morphology to form English words. However, Bonnie, an orangutan that Shumaker worked with at the National Zoo in Washington, DC, demonstrated a series of whistles that she used to let caretakers know her needs. “And she did this without training,
essentially creating her own vocabulary and syntax to go with it,” says Shumaker.

Experiments at the think tank at the Smithsonian National Zoological Park in Washington, DC, display this innate ability. Chikako Suda-King, on a postdoc fellowship with the David Bohnett Foundation at the Smithsonian, took me behind the scenes one autumn day to meet the famous Brainy Bonnie, the orangutan that Shumaker had worked with. When Suda-King walked into the cage area, Bonnie started to act like an excited kid, but soon grew serious when she saw Suda-King roll a computer up in front of her cage. She promptly settled down in front of her computer screen.

Suda-King was trying to determine
if Bonnie had the ability to make decisions based on the perception of her own knowledge of a given subject. In other words, was she capable of asking herself: Do I know enough to take this test? This is a level of self-awareness that was previously thought unique to humans. On this day Suda-King presented five pictures, all of the same thing, which the orangutan individually tapped to move forward in the game. The next screen gave Bonnie a choice of two pictures presenting options that she had learned to translate as follows: Do you want to go to a second test of your recall of those photos and get three grapes, or do you want to opt out of the test and take only one grape? If the animal chose to take the test and missed, she got nothing. During the test phase, she was shown several photos; only one was similar to those in the study phase.

Bonnie picked the test over and over, and consistently matched the correct photos. Suda-King, who holds a PhD in animal psychology, had to slip Bonnie her three-grape rewards through a slot between them, and today Suda-King was having trouble keeping up with the orangutan. “We’re going to have to make this test harder for her,” she joked, though she admitted it had actually taken Bonnie a couple of years to figure the test out. Still, it proved self-awareness in a primate.

Sue Savage-Rumbaugh, a research scientist at the Great Ape Trust in Des Moines, Iowa, claims her bonobos, relatives of chimpanzees,
are able to communicate with caregivers through human
sign language and a system of lexicons. Savage-Rumbaugh says her bonobos are allowed to watch soap operas, which they select and turn on themselves, and they have shown a preference for sequential stories.

Lisa Heimbauer, a doctoral candidate at Georgia State University, taught a chimpanzee called Panzee to understand English by treating the chimp like a human from shortly after it was born. Panzee can currently understand 130 human words even when those words are offered in computer-distorted speech that was thought to disguise those words from anyone other than humans. Heimbauer believes that primates developed understanding before speaking. “The
cognitive abilities to perceive speech had to be there when production evolved,” she told me in a telephone interview.

Though both Neanderthals and
Homo erectus
are thought to have had some form of basic speech,
Homo sapiens
were better at acquiring and advancing it. This gave them a dramatic advantage over other hominids because they could engage in trade while learning to navigate the wildly fluctuating climate of the ice ages. In
The Third Chimpanzee: The Evolution and Future of the Human Animal
, Jared Diamond describes this as the “Great Leap Forward,” or the dawn of culture. Speech involves a series of mental images or symbols that represent words and thoughts. Though there is no direct evidence of speech in Neanderthals, there is evidence of common tool use that must have required some sort of communication between the different hominids, and possibly interbreeding. The latter may be responsible for shared genes in both species, particularly
the FOXP2 speech gene, which anthropologists say
Homo sapiens
may have picked up from Neanderthals.

Speech may have given modern man the same advantage that large lungs gave
Lystrosaurus
, the bulldog with tusks, during the Permian extinction. Like man,
Lystrosaurus
grabbed this advantage and populated
much of the world, as did the newly evolved dinosaurs after the Triassic extinction: they seized the advantage from the then-dominant crocodile-like predators, and soon ruled the world.

Today, modern man is the planet’s most successful creature, occupying virtually every environment on earth except the deep ocean and the polar ice caps. But our population growth of
Homo sapiens
has reached a zenith in the last fifty or sixty years, and we are now at the point where our celebrated progress has become our greatest nightmare.

The population boom of Los Angeles, California, shows how growth can rapidly accelerate with little notice by the residents but with great consequences for the environment.
The town was established in 1781 when the Spanish governor at the time convinced 44 people to come up from Mexico to investigate the possibilities of this new and untrammeled land. By 1800, the 44 people who had settled there grew to 315 people. By 1850, after Mexico had ceded California to the United States, there were 1,610. By 1900, there were 102,479. Then they found oil in some of the beach towns. In the 1910s and 1920s the film industry moved from New York out to the West Coast for better weather. With the breakout of World War II, they started building planes. By 1950, in an area of about 502 square miles—smaller than London or Tokyo but bigger than New York—there were 1,970,358 people living.

I grew up in Los Angeles’s Westside when it was mostly single-family dwellings. Traffic on the street was light, and there were few freeways. Then the government started building freeways and moving my friends out, buying up their property for public use under the government right of “eminent domain.” Over time, the single-family dwellings turned to multiple dwellings. The former apartments turned to apartment towers. My family used to drive east toward the mountains or the desert and we would gaze at orange groves all along the way. Now there are homes, apartments, car lots, and mega-malls.
Today the population is close to 3.9 million. And most of this growth, both the human population and the infrastructure,
developed in the last one hundred years.

A similar tale of growth is true for New York City. When the surveyor John Randel Jr. submitted his intricate grid of the streets of Manhattan in 1811 that would eventually develop into Greenwich Village, SoHo, Times Square, and all its famous communities, this central isle surrounded by rivers was but a New York City borough of eighteenth-century villages. “The island was hilly and stony, woven with creeks, soft in places with beaches, marshes, and wetlands,” writes Marguerite Holloway, author of
The Measure of Manhattan
, the story of Randel’s grand achievement. In 1800 the city’s population was 60,000. Today the Census Bureau shows New York is the most populous metropolitan area in the US, with an estimated 8.4 million residents.

In those two hundred years, London has grown from about 960,000 to 2.8 million. In one hundred years, Tokyo has grown from 3.7 million to 13.2 million. Istanbul grew from 3.7 million to 13 million. When you include the immediate suburbs around these cities, estimates can more than double. As the population of the world has risen, so has the population of its great cities.

If we were to make a chart of the
world’s population growth, it would look a lot like the Keeling Curve, which shows the growth of CO
₂
in the atmosphere in the last thousand years. It’s often referred to as a hockey stick, because CO
₂
emissions remained steady for most of this period until 1850, when the Industrial Revolution swung into gear worldwide and amounts grew from 280 ppm (parts per million) to 396 ppm today. The world population in
AD
1 was about 200 million. It increased slowly over the first millennium, but started accelerating in the second millennium, particularly toward the end. By around 1800 it was at 1 billion. By 1930 it was 2 billion; 1987, 5 billion. By 2011, 7 billion. By 2024, it is predicted to reach 8 billion, and by 2045,
9 billion. If the world continues to grow as it has in the last fifty years its population could reach 27 billion by the year 2100, which is unsustainable. Among a ton of other issues, there simply wouldn’t be enough food to feed that many people.

Population experts are relying on a radical slowdown of this growth brought on by national controls, but also by women holding off childbirth to take advantage of increasing opportunities in industry and education. Many scientists project that population growth could start to level off during this century, and by 2100 we may be only ten billion. Still, that figure represents three billion more people on earth than there are today.

The largest population growth has occurred in Asia and Africa. From 1960 to 2011, India gained 782 million people, the single largest contribution to the planet’s population in the world. By 2030, India’s population is expected to top China’s. In India, women have an average of 2.5 children each. But by 2030 the rate is expected to fall to 2.1 children, close to the replacement rate of 2 per couple. The problem is that over the last fifty to sixty years we’ve come through the largest population boom in the history of man, and this has momentum. United Nations demographers used to think it would peak in 2075. Now they say it will continue to grow into the next century.

There are cultural barriers to population control. Fertility is still advanced by tradition, religion, the lower status of women, and limited access to contraception. In the US, support for family planning has actually dwindled. Population growth today gets less attention than it did in the 1960s, when there were only half as many people alive.

India’s population growth has slowed among the urban middle class but remains high among the rural poor. Producing a male heir is still a family tradition in the Hindu culture. Sons provide for their parents in old age and perform last rites, a duty seen as necessary for access to heaven. Having ten or fifteen grandsons is still considered a healthy sign by some Indian grandparents.