Final answer:
The development of the theory of plate tectonics was significantly influenced by Alfred Wegener's concept of continental drift, based on the fit of continental edges and fossil records, and later by Harry Hess's idea of sea floor spreading.
Step-by-step explanation:
Evidence Leading to the Theory of Plate Tectonics
The theory of plate tectonics is a fundamental concept in geology that explains the movement of Earth's lithosphere. The development of this theory was significantly influenced by two main types of evidence. First, Alfred Wegener's observation that continents appeared to fit together like pieces of a puzzle, which suggested they were once joined in a supercontinent known as Pangea. Second, the discovery of matching fossil records and geological formations, like mountain ranges, across different continents, supported the idea that landmasses were once connected and have since drifted apart. Wegener's initial hypothesis of continental drift, although not fully accepted at the time due to the lack of a mechanism to explain the movement, eventually evolved into the theory of plate tectonics with further evidence like sea floor spreading proposed by Harry Hess in the 1960s.
These discoveries, in conjunction with studies of seismic activity, ocean floor mapping, and the understanding of how heat from Earth's interior causes mantle convection, solidified the theory of plate tectonics in the scientific community. By juxtaposing fossil evidence and the fitting edges of continental shelves, the scientific world realized the plausible movement of continents, leading to the grand unifying theory we know today which explains not only the drifting of continents but also the prevalence of natural phenomena such as earthquakes, volcanoes, and mountain-building processes.