The Next Species: The Future of Evolution in the Aftermath of Man by Michael Tennesen Page B

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, particularlythe 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 populatedmuch 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