explain how the theory of continental drift changed when new evidence was discovered.

The theory of continental drift, initially proposed by Alfred Wegener in 1912, suggested that all the continents were once part of a supercontinent called Pangaea and have since drifted apart to their current positions. Wegener's theory was based on several key pieces of evidence such as the jigsaw-like fit of continental coastlines, matching rock formations and mountain ranges on different continents, and the presence of identical fossils on continents now separated by oceans. However, Wegener's theory initially lacked a convincing mechanism explaining how continents could move, which led to skepticism and limited acceptance among scientists at the time. The substantial change in the theory came with new evidence and understanding that emerged mainly in the mid-20th century. Advances in technology and ocean exploration revealed features like the Mid-Atlantic Ridge and patterns of magnetic striping on the ocean floor, showing that new oceanic crust was being created and pushing continents apart. This supported the concept of seafloor spreading. Additionally, the theory of plate tectonics was developed, which provided a robust framework and mechanism: the Earth's lithosphere is divided into tectonic plates that float on the semi-fluid asthenosphere beneath. Forces such as mantle convection, ridge push, and slab pull drive the movement of these plates, explaining how continents drift over geological time. Thus, the theory of continental drift evolved from Wegener's initial hypothesis of drifting continents without a clear mechanism, to the broader, mechanistically explained theory of plate tectonics that integrates continental drift with seafloor spreading and plate movements. This shift transformed the understanding of Earth's dynamic surface and resolved the earlier objection about how continents could physically move.