The Phoenicians inhabited the Maltese Islands from around 700 BCE, and made extensive use of their sheltered harbours. By 480 BCE, with the ascendancy of Carthage in the western Mediterranean, Malta became a Punic colony. Phoenician origins have been suggested for the Maltese people and their customs since 1565. A genetic study carried out by geneticists Spencer Wells and Pierre Zalloua of the American University of Beirut argued that more than 50% of Y-chromosomes from Maltese men may have Phoenician origins.