ELECTROPHORETIC AND MORPHOLOGICAL ANALYSIS OF THE SYSTEMATICS OF THE PHALANGER-ORIENTALIS (MARSUPIALIA) SPECIES COMPLEX IN PAPUA-NEW-GUINEAAND THE SOLOMON-ISLANDS

Three electrophoretically and morphologically distinct populations pre viously referred to Phalanger orientalis are recognised within Papua N ew Guinea and the Solomon Islands: Phalanger orientalis orientalis fro m northern Papua New Guinea and some nearby offshore islands, Phalange r orientalis breviceps from the Bismarck Archipelago and Solomon Islan ds, and Phalanger intercastellanus from eastern and southern Papua New Guinea and the islands of Milne Bay. P. o. orientalis is genetically and geographically relatively uniform. P. o. breviceps may have been i ntroduced by humans over most of its range, and it is extremely variab le, even within island populations. P. intercastellanus shows consider able intraspecific geographic variation, and is genetically divergent from P. o. orientalis (Nei's unbiased distance of 0.216) and P. o. bre viceps (Nei's unbiased distance of 0.171). Indeed, this divergence is so marked that the previously recognised taxa Phalanger carmelitae and Phalanger vestitus are apparently genetically closer to P. orientalis than to P. intercastellanus.