Father of Us All?

摘要

To start with, it is nearly 7 million years old-a million years more ancient than the previous record holder. Indeed, this new species is as much older than the famous Lucy as Lucy is older than we are. It almost certainly dates from very near that crucial moment in prehistory when hominids began to tread an evolutionary path that diverged from that of chimps, our closest living relatives. Even more surprising, this ancient hominid was not discovered anywhere near the Great Rift Valley of East Africa, where all the record setters of the past three decades have been found. Instead, it turned up in the sub-Sa-haran Sahel region of Chad, more than 1,500 miles to the west, forcing a rethinking of the conventional wisdom about where humans arose.