Samples of the male Y-chromosome were collected from 1,330 men now living at six sites known to have been settled in antiquity as colonies and trading outposts of the Phoenicians. The sites were in Cyprus, Malta, Morocco, the West Bank, Syria and Tunisia.

Each participant, whose inner cheek was swabbed for the samples, had at least three generations of indigenous ancestry at the site. To this was added data already available from Lebanon and previously published chromosome findings from nearly 6,000 men at 56 sites throughout the Mediterranean region. The data were then compared with similar research from neighboring communities having no link to Phoenician settlers.

From the research emerged a distinctive Phoenician genetic signature, in contrast to genetic traces spread by other migrations, like those of late Stone-Age farmers, Greek colonists and the Jewish Diaspora. The scientists thus concluded that, for example, one boy in each school class from Cyprus to Tunis may be a descendant of Phoenician traders.

“We were lucky in one respect,” Pierre A. Zalloua, a geneticist at Lebanese American University in Beirut who was a principal author of the journal report, said in an interview. “So many Phoenician settlement sites were geographically close to non-Phoenician sites, making it easier to distinguish differences in genetic patterns.”

In the journal article, the researchers wrote that the work “underscores the effectiveness of Y-chromosomal variability” in tracing human migrations. “Our methodology,” they concluded, “can be applied to any historically documented expansion in which contact and noncontact sites can be identified.”

Dr. Zalloua said that with further research it might be possible to refine genetic patterns to reveal phases of the Phoenician expansion over time — “first to Cyprus, then Malta and Africa, all the way to Spain.” Perhaps, he added, the genes may hold clues to which Phoenician cities — Byblos, Tyre or Sidon — settled certain colonies.

Dr. Wells, a specialist in applying genetics to migration studies who is also an explorer-in-residence at the National Geographic Society, suggested that similar projects in the future could investigate the genetic imprint from the Celtic expansion across the European continent, the Inca through South America, Alexander’s march through central and south Asia and multicultural traffic on the Silk Road.