The model supports a 70-year-old theory that mainland mammals from southeastern Africa “rafted” to the island on large logs or floating carpets of vegetation after being swept out to sea during storms.
The ancient refugees were carried to Madagascar by ocean currents, drifting on the open seas for several weeks before finally coming ashore, the model says.
Based on genetic and ecosystem evidence, this theory makes more sense than the alternative, which holds that Madagascar’s mammals arrived via a land bridge that was later destroyed by shifting continents.
One of the problems with the rafting theory was that ocean currents and prevailing winds around Madagascar today move east to west—away from, not toward, the island.
Now, using computer simulations normally employed to study global warming, scientists think the currents might have been more favorable for drifitng to Madagascar 50 million years ago.