New analysis traces group’s origins to South America
The kangaroo’s twisted marsupial family tree is now in order thanks to — you guessed it — jumping genes. Genetic evidence shows that a South American ancestor gave rise to all Australian marsupials, and that the South American opossums were the earliest group to branch off from the other six marsupial clans.
Distinctive for raising their live-born young in protective pouches, marsupials all trace back to a common ancestor that split off from the rest of the mammals about 130 million years ago. But fossil and genetic evidence conflict about which marsupial species evolved first, and where.