Final answer:
Alfred Wegener used four main points to support the existence of Pangea: the jigsaw puzzle-like fit of the continents, matching fossils across separated lands, corresponding mountain ranges, and paleoclimate evidence indicating different past latitudinal positions.
Step-by-step explanation:
The four points Alfred Wegener used as evidence for Pangea's existence were compelling during his time and form the foundation of what we now understand as plate tectonics.
Firstly, Wegener noted that the continents fit together like pieces of a puzzle, most notably the congruent coastlines of South America and Africa.
Secondly, he found that there were matching fossils on continents that were currently separated by vast oceans.
Thirdly, Wegener observed matching mountain ranges across these divided lands.
Finally, he pointed to paleoclimate evidence, indicating that continents had experienced climate conditions consistent with different latitudinal positioning than their current locations.
Despite his groundbreaking observations, Wegener's theory of continental drift was initially rejected due to a lack of a mechanism explaining the movement of the continents.