Platyrrhine noses dominate in all groups which have long been native to humid tropical climate. An exception is people of America and South-East Asia, as the native groups there stem from comparatively recent migrations (a few millennia old) from the North. Much of Sub-Saharan Africa is platyrrhine, from the moist savannahs of the North to the rainforests and the southern steppes as well as large parts of Madagascar. In Asia, platyrrhiny is often only mild. It is found in some ancient Indian tribal groups, as well as Dayaks and some Indochinese mountain tribes. Platyrrhiny dominates throughout New Guinea and Melanesia, and most of South Australia. In America only a few Lagoid groups of the tropics as well as the oldest Californian tribes show platyrrhiny.