Two fossils found in Kenya have shaken the human family tree, possibly rearranging major branches thought to be in a straight ancestral line to Homo sapiens. Scientists who dated and analyzed the specimens – a 1.4-million-year-old Homo habilis and a 1.5-million-year-old Homo erectus – said their findings challenged the conventional view that these species evolved one after the other. Instead, they apparently lived side by side in eastern Africa for almost half a million years. If this interpretation is correct, the early evolution of the genus Homo is left even more shrouded in mystery than before. It means that both habilis and erectus must have originated from a common ancestor between 2 million and 3 million years ago, a time for which the fossil record is virtually blank. Although the findings do not change the relationship of Homo erectus as a direct ancestor of Homo sapiens, scientists said, the surprisingly diminutive erectus skull implies that this species was not as humanlike as once thought. Other paleontologists and experts in human evolution said the discovery strongly suggested that the early transition from more apelike to more humanlike ancestors is still poorly understood. They also said this emphasized […]