Randomly amplified polymorphic DNA variation in populations of eastern Australian koalas, Phascolarctos cinereus

Randomly amplified polymorphic DNA (RAPD) variation in populations of the k oala, Phascolarctos cinereus, was investigated, revealing significant diffe rences in the level of diversity between southern and northern regions of e astern Australia. Of the 20 polymorphic RAPD markers identified in koalas, 4-7 were polymorphic in southern populations, while 12-17 were polymorphic in northern populations. Analysis of molecular variance revealed a signific ant difference in the estimated variance between koalas from northern and t hose from southern regions (P < 0.001), where populations from the north we re greater than twice as variable as their southern cousins. The total gene tic diversity observed was attributed to regional differences (30.91%), pop ulation differences within a region (11.77%), and differences among individ uals within a population (57.32%). For the within-region analyses, a large proportion of the genetic diversity was attributable to individual differen ces within a population, 80.34% for the north and 91.23% for the south. The se results demonstrate that RAPD markers are useful for determining populat ion structure among koalas.