Skulls Found in Africa and in Europe Challenge Theories of Human Origins

Two ancient skulls, one from central Africa and the other from the Black Sea republic of Georgia, have shaken the human family tree to its roots, sending scientists scrambling to see if their favorite theories are among the fallen fruit. Probably so, according to paleontologists, who may have to make major revisions in the human genealogy and rethink some of their ideas about the first migrations out of Africa by human relatives. The African skull dates from nearly 7 million years ago, close to the fateful moment when the human and chimpanzee lineages went their separate ways. The 1.75-million-year-old Georgian skull could answer questions about the first human ancestors to leave Africa, and why they ventured forth. Dr. Daniel E. Lieberman, a biological anthropologist at Harvard, called the African specimen "one of the greatest paleontological discoveries of the past 100 years."