POPULATION-GENETICS OF EULEMUR-MACACO-MACACO (PRIMATES, LEMURIDAE) ONTHE ISLANDS OF NOSY-BE AND NOSY-KOMBA AND THE PENINSULA-OF-AMBATO (MADAGASCAR)

Analysis for genetic variation of insular and mainland populations of Eulemur macaco has revealed: (1) a different degree of genetic variati on between populations; and (2) the phylogenetic relationships between groups, on the islands of Nosy-Be and Nosy-Komba, and in the Peninsul a of Ambato (Madagascar). Eleven systems of blood proteins from 157 an imals were used as genetic markers. The genetic variation was lower on the island of Nosy-Komba than in the mainland of Ambato. This is cons istent with the expectation that genetic variation is lower on islands than on mainlands. In contrast, the genetic variation on the island o f Nosy-Be was the highest of the three populations. This finding can b est be explained by assuming that the sample of Nosy-Be consists of in dividuals of several small isolated groups, where genetic drift comput ation showed the population of Nosy-Be to be distinct, and the populat ions of Nosy-Komba and Ambato to be close within the same branch of th e dendrogram. These findings give an insight into the population histo ry of the island of Nosy-Komba, which might have been populated by mai nland groups from Ambato.