The Next Species: The Future of Evolution in the Aftermath of Man by Michael Tennesen Read Free Book Online

were Nicholas Toth, Kathy Schick, and James Brophy, all professors at Indiana University, who were traveling to Olduvai Gorge. The car contained several weeks’ worth of gear, supplies, and personal belongings, as well as a pop-up roof that allowed us to view and take pictures of the wildlife along the way without getting eaten.
    We gradually approached the green jungle that shrouded the Crater Highlands of the Eastern Rift Valley, as the sun boiled up the midday tropical clouds into the sky. By early afternoon we crested the rim of Ngorongoro Crater and descended into the ancient cauldron.Ngorongoro Crater became a UNESCO World Heritage Site in 1979. At our first look into the crater, it seemed vacant: some little specks down there—rocks perhaps—but not much wildlife.
    As we wound down the inside wall of the cauldron, these specks grew more and more spectacular. The first group we came upon turned out to be a herd of Cape buffalo. For the most part the animals ignored the tourist vehicles. They moved about in small groups and herds, feasting on the savanna grasses that covered the crater’s floor. One buffalo stood and stared at our truck. It appeared mean and perturbed. Masoy claimed that buffalo are some of the most dangerous of Africa’s wildlife, partly because there are so many of them and partly because people don’t take them seriously. I could only count them in batches, each containing perhaps fifty animals. There are at least twenty other batches within our field of view, perhaps one thousandanimals in all.
    We spot a pair of rhinos. They keep their distance, maybe two hundred yards away. That afternoon we spot about fifteen hundred zebras, two thousand wildebeest, one thousand buffalo, several bustards (a large terrestrial bird), black-crowned cranes, impalas, six hyenas, about eight jackals, one African lion, one cheetah, and eight giraffes.
    But the surprise of the day came when we spotted three elephants in Ngorongoro Crater walking through a crowd of several hundred zebra. One elephant was tuskless; another seemed to have broken one of its tusks. None had a glorious pair of ivory as in your typical African photo. This was evolution in action. The tusks of the big elephants are a gold mine and too dangerous for the animals to carry.
    Despite the government threat to shoot poachers on sight, poachers keep trying. Similar to other parts of the world, Africa is losing its animals. Neither strict national laws nor international support nor tourist income completely protects these majestic animals from illegal hunters. Congolese authorities recently accused the Ugandan military of killing twenty-two elephants from a helicopter and then carting away more than a million dollars’ worth of ivory.
    In the 1970s, 10 to 20 percent of all the elephants in the wild were killed. At that rate, extinction could have come quickly, but international pressure and evolution have given the elephants a reprieve. Poaching put evolutionary pressure on animals with tusks, and tusks on elephants began to disappear rapidly. Ownership of ivory tusks was too expensive.
    Selection has affected both male and female elephants. A Prince-ton ecologist, Andrew Dobson, traced the evolution of tusklessness in females at five African wildlife preserves. In one park where elephants were relatively safe, the incidence of tusklessness in females was small, a few percent. But in another park where they had been heavily poached, it was a different story. Females aged five through ten were about 10 percent tuskless. But females aged thirty to thirty-five were about 50 percent tuskless.
    Researchers have noted similar results for males. That nature would allow male elephants to give up their tusks is phenomenal.Males use their tusks to battle each other for access to the females. A male without tusks is like a knight without a lance; yet, due to the state of game hunting, tuskless males have a better chance of surviving. Thus nature now selects