WASHINGTON (AP) - About 80% of Europeans arose from primitive hunters who arrived about 40,000 years ago, endured the long ice age and then expanded rapidly to dominate the continent, a new study shows. Researchers analyzing the Y chromosome taken from 1,007 men from 25 different locations in Europe found a pattern that suggests four out of five of the men shared a common male ancestor about 40,000 years ago. Peter A. Underhill, a senior researcher at the Stanford Genome Technology Center in Palo Alto, Calif., and co-author of the study, said the research supports conclusions from archaeological, linguistic and other DNA evidence about the settlement of Europe by ancient peoples. "When we can get different lines of evidence that tell the same story, then we feel we are telling the true history of the species," Underhill said. The researchers used the Y chromosome in the study because its rare changes establish a pattern that can be traced back hundreds of generations, thus helping to plot the movement of ancient humans. The Y chromosome is inherited only by sons from their fathers.