Skull said to confirm Homo erectus as modern man's global predecessor
PORTLAND, Ore. (AP) A million-year-old skull found in Ethiopia confirms the theory that modern man evolved from a single prehuman species that developed in Africa and migrated throughout much of the world, scientists say.
Most anthropologists believe that Homo erectus the species that is said to bear the first recognizable human characteristics emerged nearly 2 million years ago in Africa and spread across several continents to serve as an ancestor to modern man, or Homo sapiens.
But some scientists maintain that another prehuman species known as Homo ergaster emerged in Africa about the same time, migrated around the world and evolved into Homo erectus. Then, according to this theory, Homo erectus traveled to Africa.
Researchers from the United States and Ethiopia said this latest skull appears to be Homo erectus. They said the find helps prove that Homo erectus originated in Africa and persisted there for hundreds of thousands of years, while some of its numbers migrated around the world.
In fact, they said the differences discovered around the world between Homo erectus and specimens considered to be Homo ergaster primarily variations in facial and skull bones are too minor to represent different species and that Homo ergaster did not exist as a separate species.
The study was led by University of California, Berkeley, anthropologist Tim White and was published in Thursday's issue of the journal Nature.
"There's been a recent tendency to give a different name to each of the fossils that comes out of the ground, and that has led to what we think is a very misleading portrayal of the biology of human evolution," said White, who co-directs the Laboratory for Human Evolutionary Studies.
"But when you find a fossil like this one so similar to Asian and European ones, it indicates the same species." Unlike earlier prehuman species with apelike traits, Homo erectus had a large brain and walked upright. It made stone tools and ate meat.
Within several thousand years, it had moved into the Middle East, Europe and southern Asia, though the precise pattern remains uncertain. It became extinct 400,000 years ago.
The Neanderthals in Europe probably were a later branch of Homo erectus that became extinct, White said, but may have overlapped with early Homo sapiens.
Other anthropologists called the Ethiopian skull an important find, but said it does not resolve the debate.
"This whole species question is all about what you accept as a sharp enough distinction to tell you that it is a separate species," said Susan Anton, a Rutgers University anthropologist. "This particular skull is not going to solve that problem."