Genetic studies that show the first modern human arrived in China about 60,000 years ago support the theory that people first evolved in Africa, researchers say.

In a study published Tuesday in the Proceedings of the National Academy of Sciences, scientists say that an analysis of genetic samples from throughout Asia suggests that people there sprang from common ancestors, the modern humans who appeared first in Africa and then spread throughout the world."Our work shows that modern humans first came to southeast Asia and then moved later to northern China," said Li Jin, a population geneticist at the University of Texas in Houston. "This supports the idea that modern humans originated in Africa."

Jin said the study is based on analysis of the gene patterns from 43 different ethnic groups in China and Asia. He said the technique gives an indication of how people moved and mixed over thousands of generations.

Migration clues are carried in genetic patterns, called micro-sat-ellites, that change rapidly over time. By analyzing these changes and linking them to earlier genetic patterns, researchers are able to plot the migration of ancient humans.

Based on the research, Jin said it appears that modern humans first moved from central Asia, following the Indian Ocean coastline across India, to southeast Asia. Later, they moved to south China. Descendants of these original Chinese then migrated north and northwest, populating northern China, Siberia and eventually the Americas.

"This is important research because it supports the out-of-Africa theory about the origin of modern humans," said Ranjan Deka, a population genetics researcher at the University of Cincinnati.

Deka said the results of the study weaken an alternative theory that modern humans arose independently on different continents at about the same time.