Getting the drift on continental shifts.

It doesn't take great detective skills to notice that the coastlines of South America and Africa would fit nicely together if the two sat side by side. This observation, followed by others, led German meteorologist Alfred Wegener in 1912 to propose the theory of continental drift, which holds that the landmasses migrate around the planet, sometimes colliding and other times rifting. Although scientists give Wegener and others of his time credit for formulating the drift hypothesis, a researcher has now traced elements of the idea back three centuries earlier, to a Dutch cartographer named Abraham Orielins.

James Romm, a professor of classics at Bard College in Annandale-on-Hudson, N.Y., reports in the Feb. 3 NATURE that Ortelins in 1596 suggested the continents once were joined but later separated. In his work Thesaurus Geographicus, Ortelius postulated that earthquakes and floods tore America from Africa and Europe: "The vestiges of the rupture reveal themselves, if someone brings forward a map of the world and considers carefully the coasts of the three [continents]."

Romm happened upon Ortelius' theory while researching the history of the Atlantis myth. As was common in Ortelius day, the cartographer equated the Americas with the lost city of Atlantis. But he went beyond others by suggesting that Atlantis moved away from the other continents instead of sinking, as had been suggested. Romm speculates that Ortelius' contribution went unnoticed for so long because it appears only once in the middle of his long volume.

Ortelius supplants a long line of other philosophers credited with formulating the idea of continental drift. While Wegener was one of the first to present a fleshed-ut scientific theory of drift, historians until recently viewed a book written by Francis Bacon in 1620 as the first to mention that the continents could fit together. Yet Bacon missed the entire point, says Romm. Instead of recognizing that the continents had complementary coastlines, he suggested that some landmasses had similar shapes, as if cut by the same mold. After severing Bacon's hold on the honor, historians have since named an 18th century theologian and a 19th century geologist as potential originators of the continental drift theory.

Although people today might find it obvious that the continents could fit together like pieces in a jigsaw puzzle, Romm says the match became self-evident only alter the theory of continental drift gained widespread circulation. "Without an explanation of what that might mean, it was very hard to see the phenomenon itself."