For a discovery so vital, the fossil looks unimpressive: a yellowed chunk of lower jaw with molars and space for a tusklike fang. But it is already helping scientists reshape their theories about our shared ancestors with the apes - and may change their travel plans as well. The first fossil of its kind found in southern Africa, it seems likely to attract further research in the region. “This fossil is something that no one else has seen,” says expedition leader Glenn Conroy of Washington University in St. Louis. The living animal likely had features of both humans and apes, and was smaller than human beings. It is clear the unknown animal was related to humans, but scientists have yet to find its place on the evolutionary map. There are few signposts to go by: pre-human fossils more than 4 million years old are almost unknown.
While the Namibian fossil links humans to the past, new findings on Neanderthals show the evolutionary road not taken. In a paper published last week in the British journal Nature, French scientists reported that they had found Neanderthal remains and complex tools approximately 36,000 years old. Theirs was a twofold discovery: that Neanderthals were around more recently than scientists believed, and were also quite intelligent. One previous theory held that Neanderthals, who roamed Europe beginning 200,000 years ago, evolved into modern humans. Another hypothesis said the species was immediately wiped out by modern man 40,000 years ago. The French discovery suggests the truth lies between those two extremes. A variety of factors (including competition for food from modern humans, perhaps warfare or even disease) probably caused Neanderthals to decline over 5,000 years. “Neanderthals were physically different from people alive today,” says British paleontologist Christopher B. Stringer, “but in other respects they were very advanced.” The Neanderthals, we now know, caught up with the technology of their rivals. The groups whose remains were found in France had advanced tools, such as ones for carving ivory, that scientists had thought were used only by modern humans.
“Everybody has a fascination with origins,” says Conroy. “The closer it gets to yourself, the more interesting and controversial it becomes.” This century’s discoveries have already sparked new evolutionary theory, shifting the focus of research from Europe to Africa. Scientists are now filling million-year gaps in the evolutionary time chart - but each new clue only emphasizes how many more links remain missing.
