Which scientist proposed the theory that continents were once connected, leading to plate tectonics?

• A. Charles Darwin
• B. James Hutton
• C. Louis Agassiz
• D. Alfred Wegener

Answer: (D)

Continents were once connected and have moved over time, a idea that later became plate tectonics. Alfred Wegener argued that all the continents formed a single supercontinent called Pangaea and gradually drifted to their present positions. He gathered several lines of evidence to support this: the coastlines of continents like South America and Africa appear to fit together like puzzle pieces; identical fossils of certain plants and animals are found on continents that are now far apart; rock formations and mountain ranges line up when continents are rearranged to fit, suggesting they were once joined; and clues from ancient climates show glacial deposits and tropical signs in locations that would have been in different climates if they were still in their current places.

While Wegener didn’t provide a convincing mechanism for how continents moved, his proposal laid the groundwork for the broader theory of plate tectonics, which explains movement through the motion of lithospheric plates driven by processes inside the mantle. Other scientists in the list contributed important ideas in biology and geology, but Wegener is the one who first proposed the idea that continents were once connected and drifted apart, leading to the modern understanding of plate tectonics.