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

hikeddown the cliff face to a wide bend in the dry creek, a site surveyed by the Leakeys in the 1960s and more recently by the current crew.
    Codirector Njau used his work in the Serengeti on living animals and their prey to understand how crocodiles might have affected early man in Olduvai. Njau told me that the entire gorge area had been through a series of drastic climate changes since two million years ago, when Homo habilis first occupied it. He said it was much more humid then, and that there was a lake not too far downstream from where we stood into which the river flowed. Today, the area was very dry with the exception of a few months of the rainy season when the Olduvai River floods briefly.
    Homo habilis took meat here, but not as a hunter. “Most people think, ‘Oh, here comes man, he must have been a hunter,’ ” said Njau, “but no, Homo habilis was only about three or four feet tall, and weighed less than one hundred pounds. There was no way he could have brought down wildebeest-or gazelle-sized animals here. We think he lived here as a scavenger, feeding off the kills of lions and leopards.”
    In order to survive like this, he had to be well aware of the terrain, and he had to forage in groups. One man alone was too much of a target for local predators. The Leakey family originally hypothesized that early man may have lived along the waters running through Olduvai, but Njau thought that the evidence for crocodiles, hyenas, leopards, and lions as well as hippos, elephants, and other wetland animals was too great and the result too dangerous for men to have stayed here on any type of permanent basis. He considered this space more as a puzzle that H. habilis had to learn to navigate, and that an ability to plan, to hunt cooperatively, and to anticipate predator movements would have provided selective pressure for early human intelligence. If you didn’t figure out the puzzle, you died and didn’t pass on your genes—the basic element of evolution.
    Fossil evidence for tool use at Olduvai showed that H. habilis had instruments for cutting flesh away from bones, but not stone spear-or arrowheads that could kill fully grown animals or drive off lethalpredators. They may have had wooden spears, but they were scavengers, not hunters. Being smart here improved their chances of survival but also provided access to meat, which had the extra calories necessary to evolve bigger brains.

    Studies of the lineage of man provide not only a look at the past but also insight into the future. It was only in 1856 that scientists found the fossilized bones of the first extinct human in the Neander Valley, Germany. Darwin mentioned nothing in On the Origin of Species about the evolution of man, though the book came out in 1859, three years after the first Neanderthal fossil was discovered. It was not until 1864 that these fossils were recognized as a separate species, Homo neanderthalensis .
    Darwin later proposed that our early ancestors diverged from Old World monkeys in the early Miocene epoch, about 20 million years ago. In 1927, Dr. H. L. Gordon, a retired government medical officer, found in limestone deposits in western Kenya a specimen of one of the first primates to diverge from apes. Gordon named it Proconsul africanus , after a chimpanzee named Consul that performed in the Folies Bergère in Paris in the early 1900s. The Folies chimp wore a tux, played the piano, and smoked a cigar, before taking off his trousers, standing on his head, and somersaulting into bed. Mary Leakey found one of the most complete skulls of Proconsul in 1948 on Lake Victoria.
    The discoveries of early primates leading up to man didn’t end with Proconsul . Africa had many more tales to tell. Australopithecus afarensis (better known as Lucy, which lived from 3.85 million to 2.95 million years ago) was discovered in 1974 by American paleontologist Donald Johanson and grad student Tom Gray. They found Lucy in Hadar, Ethiopia, and celebrated