First Humans pdf por Rebecca Stefoff
First Humans (Humans: An Evolutionary History)
Dogs and bones just seem to go together. Canines gnawing bones, or burying them, are the subject of countless pictures and cartoons. Dogs are also linked to the discovery of a famous fossil bone although they did not dig up the ancient relic, or even chew on it. Mary Leakey went walking with her dalmatians on July 17, 1959. The place was Olduvai Gorge, a dry, narrow canyon in the East African nation of Tanzania, which was called Tanganyika at that time. Since the 1930s Leakey and her husband, Louis Leakey, had spent much of their time in a tent camp at Olduvai, digging into the past. They had unearthed many fossils, remains of ancient animal and plant life that had turned to stone over long periods of time. Among the vanished creatures that had once roamed that part of Africa were deinotheres, elephantlike beasts with tusks that grew downward from their lower jaws. But the Leakeys had found more than fossils in Olduvai Gorge. They had also found pebbles from which flakes had been knocked off, creating sharp edges. These edges did not form by chance. They were deliberately crafted so that the pebbles could be used as cutters or choppers.