He first comprehensive theory of continental drift was proposed by in the early twentieth century.

Alfred Wegener

Explanation:

The first comprehensive theory of continental drift was suggested by Alfred Wegner. The theory tells us that the world a long time ago, was a single continent called Pangea. That continent throughout the years separated and drifted away, creating the seven continents that we know nowadays. Wegener expressed that the continents are not rigidly fixed but are moving very slowly. The theory that backed up this theory, was the theory of plate-tectonics. This theory mentions the constant moving of the plates, in a very slow pace.

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