The Scientific Journals

It’s quite a tale. Perhaps five million to 10 million years ago, a primate species diverged from the chimpanzee line. This was the forerunner of humanity and a host of other beings who were almost but not quite human. For a time, a throng of hominid species shared the planet; at least four even coexisted in the same region. By around four million years ago, our progenitors and others had mastered the art of walking upright. Some two million years later they strode out of Africa and colonized entirely new lands. Certain groups learned to make sophisticated tools and, later, artwork and musical instruments. The various species clashed, inevitably. Modern humans, who entered Europe 40,000 years ago, may have slaughtered Neandertals (when they weren’t interbreeding with them).  Eventually only one species, Homo sapiens, was left. We thus find ourselves alone and yet the most numerous and successful primates in history.

Reading the cracked brown fragments of fossils and sequences of DNA, however, scientists have found clues that the story of human origins has more convolutions. The account of our shared human heritage now includes more controversial plot twists and mysteries. Was the remarkable seven-million-year-old skull found
in July 2002 in Chad really one of our first forebears, or a distant dead-end cousin with precociously
evolved features? Did modern humans really originate in Africa alone, as is widely held, or in multiple locales?