The indigenous peoples of Nauru are an ethnicity, which inhabit the Pacific island of Nauru. They are most likely a blend of other Pacific peoples. The origin of the Nauruan people has not yet been finally determined. It can possibly be explained by the last Malayo-Pacific human migration (c. 1200). It was probably seafaring or shipwrecked Polynesians or Melanesians, which established themselves there because there was not already an indigenous people present, whereas the Micronesians were already crossed with the Melanesians in this area. The Nauruans have two elements of their population: the native Micronesians and the Polynesians who had immigrated long before. The Micronesians are represented through coarse, dark hair; the Polynesians are lighter brown and have smoother, black hair. Through these two extremes the diverse transitions came to exist. At about 1920, influenza spread through Nauru, which took a heavy toll on the indigenous people. In 1925 the first cases of diabetes was diagnosed by doctors. Today, depending on age, every second to third Nauruan is diabetic – a higher rate than any other country in the world.