Alfred Wegener was the influential scientist credited with developing the theory of plate tectonics. His groundbreaking work in the early 20th century proposed the idea of continental drift, suggesting that continents were once joined together and have since moved apart. Although initially met with skepticism, Wegener's theories laid the groundwork for modern geology and our understanding of Earth’s dynamic surface. His contributions have become essential to the study of geology and the processes that shape our planet, influencing future research in earth sciences.