Answer:
The theory of plate tectonics
Explanation:
Alfred Wegener, a geophysicist and meteorologist proposed the theory of continental drift to explain how the earths major land masses have moved through geologic time.
In 1912,Wegener through his rich collection of fossils was able to propound the theory of continental drift in which he stated that "continents were once joined together and they have moved to their present position today". His theory failed to identify the mechanism responsible for the drifting continents.
If a geologist finds fossils of marsupials from different continents and he correlates them to the same geologic time, the best explanation is from the view point of continental drifting as explained by Wegener's theory.
In present day, the theory has been widely replaced by the plate tectonics theory which combines reasoning from the view point of Continental drift and sea floor spreading. The theory of plate tectonics fits this problem properly.
Plate tectonics suggests that the earth's lithosphere is broken into plates which moves on top of the weak and ductile asthenosphere. During the early formative years of our planet, plates were joined together as one in a grand land mass known as Pangaea. Plate tectonics caused the lithosphere to break and move to their present positions.
