The Japan Times, December 14, 1996
Human ancestor may have coexisted with modern humans
WASHINGTON (AP) Beetle-browed, humanlike creatures may have been neighbors with anatomically modern humans in Java as recently as 27,000 years ago, researchers say. Their study suggests the primitive species lived on the Pacific island almost 1 million years after it died out in Africa.
Using new techniques to date fossils found on Java, a team of anthropologists concluded that a primitive species known as Homo erectus lived in Java between 27,000 to 53,000 years ago.
Carl C. Swisher III of the Berkeley Geochronology Center said this new date indicates that Homo erectus lived in Java at the same time that Homo sapiens, the modern human, was also there.
"These are the youngest dates ever found for Homo erectus, and it is quite startling," said Susan Anton, a University of Florida anthropologist and co-author of the study. "This is the first time that they have been shown to coexist. Even in Africa, they didn't overlap."
A report on the study will be published Friday in the journal Science.
Most experts believe Homo erectus arose in Africa about 1.8 million years ago and then spread throughout Asia. Anton said it is widely believed that Homo sapiens evolved in Africa, perhaps from Homo erectus, about 200,000 years ago and then spread into the rest of the world.
Homo erectus disappeared from Africa and Asia, but Java "was sort of a refuge" for the species, said Swisher.
Java was once connected with Asia by a land bridge, he said, but when the sea level rose, it became an island, trapping and isolating the primitive humans.
Swisher said the erectus have never been shown to have developed water transportation. But the more advanced sapien built boats and probably arrived in Java about 40,000 years ago.
This means that sapien and erectus hominids shared that island for hundreds of generations, said Anton, and suggests that the arrival of modern humans led to the demise of the primitive forms.
"I find it hard to imagine that there wasn't some effect from a new hominid moving in," she said. There is no strong evidence that warfare wiped out the Homo erectus, said Anton. It is more likely, she said, that Homo sapiens simply out-competed their primitive relatives, producing more children and learning to live more successfully.
Philip Rightmire of the State University of New York, Binghamton, said the fossils used in the study by Swisher and Anton "are pretty convincing." But, he said, there may be some "technical issues to sort out" about the age-dating.
"The results are intriguing," said Rightmire, an anthropology professor. "We need to think about what this means."
But Milford Wolpoff of the University of Michigan said he doubts that the fossils are actually Homo erectus, noting that they are very similar to Australian natives, and believes the dates are "unreliable."
Swisher said the find threatens the "regional continuity" theory, supported by Wolpoff, that holds that primitive humans arose in Africa, migrated elsewhere and that modern humans arose from these separate groups. A key part of the theory is that the Java people were the ancestors of modern Australians.
Wolpoff said the Swisher study has not disproven the Java-Australia connection.
Swisher says the coexistence in Java of both Homo erectus and Homo sapiens supports the "out of Africa" theory that all human species arose at different times in Africa and migrated in waves separated by hundreds of thousands of years.
The Java Homo erectus fossils, mostly skull fragments, were found on a terraced bank of the Solo River in Java.