What two lines of evidence supported Wegener's continental drift hypothesis?

• A. Matching the edges of continents and the distribution of fossils across vast oceans.
• B. The presence of midsize earthquakes along ridges and trenches.
• C. The alignment of magnetic anomalies across continents.
• D. The detection of hot-spots beneath continents.

Answer: (A)

The idea being tested is that continents were once connected and then moved apart. The two strongest lines of evidence Wegener pointed to are that the coastlines of continents fit together like puzzle pieces, and that similar fossils and rock sequences occur on now-distant lands. The coastlines line up so well—such as the match between parts of South America and Africa—that it looks like they once formed a single landmass. At the same time, the same species of plants and animals, and corresponding rock formations, appear on continents that are now across oceans from each other. This pattern suggests those lands were once joined and shared organisms before drifting apart.

Other signals later strengthened the overall theory of plate tectonics, like patterns of earthquakes and magnetic stripes on the sea floor, and tracks through hot spots, but they were developed after Wegener's time and are not the two lines of evidence he used.