Final answer:
Alfred Wegener supported his continental drift hypothesis with four types of evidence: the jigsaw fit of continents, matching fossils across oceans, corresponding mountain ranges, and paleoclimate data. Although his ideas were initially met with skepticism due to the lack of a movement mechanism, they eventually became foundational for the theory of plate tectonics.
Step-by-step explanation:
Alfred Wegener used four types of evidence to support his hypothesis of continental drift. The idea of continental drift was revolutionary at the time of its proposal in 1915, as it suggested that continents moved over the Earth's surface through time. Wegener's hypothesis was based on the following evidences:
- The noticeable fit of the continents, like pieces of a puzzle, particularly how the west coast of Africa and the east coast of South America seem to align.
- Matching fossils found across continents, suggesting that continents like South America and Africa were once joined, as they both had identical fossil species that could not have crossed the vast ocean.
- Correspondences in mountain ranges, with the Appalachians in North America lining up with the Caledonian mountains in Scotland and Scandinavia once the Atlantic is closed.
- Paleoclimate evidence that indicates continents once resided in different climates, revealing that they had moved from their original positions (for example, glacial deposits found in India).
Wegener proposed that these continents were once a part of a single supercontinent named Pangaea. However, the scientific community was skeptical of his hypothesis due to the lack of an explanation for the mechanism behind the movement of continents. It was only with the development of plate tectonics theory in the 1960s that Wegener's ideas were fully vindicated.
Despite the initial resistance, Wegener's concept laid the foundation of modern geology and greatly enhanced our understanding of a dynamic Earth. His dedication and innovation set a precedent in the scientific community, driving a persistent curiosity towards plate tectonics and the movement of continents.