We all have one ancestor
2002-03-27 13:50
Berkeley - A million-year-old Homo erectus skull found in Ethiopia indicates that the human ancestor was a single species scattered widely throughout Asia, Europe and Africa, not two separate species, according to an international group of scientists who discovered the skull in 1997.
Some archaeologists and anthropologists have argued that African and European populations were a different species, Homo ergaster, distinct from the strictly Asian Homo erectus.
It took University of California, Berkeley, researchers and their colleagues more than two years to clean and reassemble the crushed skull, which is described by the Ethiopian and American team in the journal Nature.
The fossil was described by Berhane Asfaw of the Rift Valley Research Service in Addis Ababa, Ethiopia, paleoanthropologist Tim D. White, professor of integrative biology and co-director of UC Berkeley's Laboratory for Human Evolutionary Studies, and UC Berkeley graduate student W. Henry Gilbert, who found the skull.
"This fossil is a crucial piece of evidence showing that the splitting of Homo erectus into two species is not justified," said White.
Widespread species
"This African fossil is so similar to its Asian contemporaries that it's clear Homo erectus was a truly successful, widespread species throughout the Old World."
The scientists also conclude in their paper that the onset of the Ice Ages about 950 000 years ago likely split the Homo erectus populations and led to their divergent evolution.
The African population of Homo erectus probably gave rise to modern Homo sapiens, the European branch perhaps became the Neandertals, or Homo neanderthalensis, while the Asian population went extinct.
Homo erectus first appeared about 1.8 million years ago and, based on the fossil evidence, quickly populated Africa, Asia and Europe.
Though it is unclear whether the species arose in Africa or Asia, a million years later the widespread populations were still similar enough to be considered a single species, White argued.
On the internet:
Sciencedaily.com