continents had fit along the current coastline. Charles Schuchert commented: Wegener was in the audience for this lecture, but made no attempt to defend his work, possibly because of an inadequate command of the English language. In 1943, George Gaylord Simpson wrote a strong critique of the theory (as well as the rival theory of sunken land bridges) and gave evidence for the idea that similarities of flora and fauna between the continents could best be explained by these being fixed land masses which over time were connected and disconnected by periodic flooding, a theory known as permanentism. Alexander du Toit wrote a rejoinder to this the following year. Alfred Wegener has been mischaracterised as a lone genius whose theory of continental drift met widespread rejection until well after his death. In fact, the main tenets of the theory gained widespread acceptance by European researchers already in the 1920s, and the debates were mostly about specific details. However, the theory took longer to be accepted in North America. Modern developments In the early 1950s, the new science of paleomagnetism pioneered at the University of Cambridge by S. K. Runcorn and at Imperial College by P.M.S. Blackett was soon producing data in favour of Wegener's theory. By early 1953 samples taken from India showed that the country had previously been in the Southern hemisphere as predicted by Wegener. By 1959, the theory had enough supporting data that minds were starting to change, particularly in the United Kingdom where, in 1964, the Royal Society held a symposium on the subject. The 1960s saw several relevant developments in geology, notably the discoveries of seafloor spreading and Wadati–Benioff zones, and this led to the rapid resurrection of the continental drift hypothesis in the form of its direct descendant, the theory of plate tectonics. Maps of the geomorphology of the ocean floors created by Marie Tharp in cooperation with Bruce Heezen were an important contribution to the paradigm shift that was starting. Wegener was then recognised as the founding father of one of the major scientific revolutions of the 20th century. With the advent of the Global Positioning System (GPS) in 1993, it became possible to measure continental drift directly. Awards and honours The Alfred Wegener Institute for Polar and Marine Research in Bremerhaven, Germany, was established in 1980 on Wegener's centenary. It awards the Wegener Medal in his name. The crater Wegener on the