The wallace line
As well as being ethnically diverse,indonesia has the second highest level of biodversity in the world after brazil,with more endemic species than anywhere else except australia.the british naturalist after brazil,naturalist alfred russel wallace 1823-1913 described a dividing line between the distribution of indonesia's asian and australasian species now know as the wallace line.the line runs north-south between lombok and bali and was caused by a deep oceanic trench that prevented the formation of any land bridge,even during the ice age.west of the line there are orangutans,monkets,tigers,rhinos,tapirs,bears and the world's only lungless frog.meanwhile in the east there are no mammals except rodents,bats and marsupials.