BEING HUMAN

The earliest fossils definitely associated with human beings go back 4.5 million to 5 million years to the species Australopithecus in East Africa, says Fred H. Smith, former chair of NIU’s Department of Anthropology and now associate dean of the College of Liberal Arts and Sciences. He is considered a worldwide expert on human origins.

“Australopithecus clearly deviated from their ape ancestry,” Smith says. “These creatures exhibited a habitual upright posture and walked in stride on two legs like us. They had relatively small canine teeth, unlike apes. Yet the slightly longer arms, the skull shape and face, with more of a projecting jaw, would remind you of an ape.”

About 130,000 years ago, modern humans, or Homo sapiens, emerged in Africa. In between Australopithecus and moderns, a number of ancient human peoples belonging to the genus Homo appeared in Africa, and later in Europe and Asia. They included Homo habilis, Homo erectus, and archaic forms of Homo sapiens, such as Neandertals.

Armed with better technology for dating fossil remains, Smith and other scientists have demonstrated that archaic and modern humans coexisted in certain areas of Europe and Asia. Smith’s research also has disproved the common notion of Neandertals as dimwitted brutes; they were actually adept toolmakers and, based on the quantities of meat in their diets, must have been intelligent, adept hunters.

But did Neandertals and other archaic humans in Europe contribute to the gene pool of modern people? Or did modern humans evolve as a separate species only from African archaic forms so intellectually advanced that they drove their inferior
contemporaries to extinction? Paleoanthropologists remain sharply divided on the issue.

Some believe the emergence of moderns can be traced genetically to one or a few African women, often referred to as “mitochondrial Eve.” Smith says the DNA evidence is far from convincing, however. He is a leading proponent of an opposing camp that advocates for a theory of assimilation.

“I established the assimilation model back in the 1980s to argue modern human emergence is related to movement out of Africa but there is a significant contribution of archaic peoples to the modern human gene pool in Europe and Asia,” he says.

“Think about the encounters of Europeans and indigenous peoples such as Australians and Native Americans in the 16th and 17th centuries. In many cases, the technology differences you saw were probably on the same level as those between Neandertals and early modern humans. The differences, both cultural and anatomical, certainly didn’t stop them from mating.”

Soon after 28,000 years ago, Smith says, the archaic peoples all but disappeared. And the proliferation of modern humans was well underway. Yet it would take more than 20 millennia before humans made the leap to civilization.