Alfred Wegener, a German meteorologist and geophysicist, proposed the theory of continental drift in the early 20th century. He presented several pieces of evidence to support his idea that the continents were once joined together in a supercontinent called Pangaea and have since drifted apart.

Here are some of the key pieces of evidence Wegener used:

1. Matching Coastlines: Wegener noticed that the coastlines of continents, particularly Africa and South America, fit together like puzzle pieces. This suggested that they were once connected.

2. Fossil Distribution: Similar fossils of ancient plants and animals were found on continents now separated by vast oceans. The presence of these fossils on distant continents strongly implied that these landmasses were once connected.

3. Rock Formations and Mountain Ranges: Geologists found that the same types of rock formations and mountain ranges occurred on different continents. This suggested a shared geological history and a past connection.

4. Glacial Evidence: Evidence of ancient glacial deposits was found on continents in the southern hemisphere, such as South America, Africa, and India. The distribution of these deposits suggested that these continents were once grouped together near the South Pole.

5. Paleoclimate Data: Wegener observed evidence of past climates, such as tropical fossils found in polar regions, that suggested the continents had been in different locations than where they are now.

Challenges and Limitations:

Although Wegener presented compelling evidence, his theory of continental drift was initially met with skepticism and resistance from the scientific community. The main criticism was that he lacked a plausible mechanism to explain how the continents could move across the Earth's surface.

The Rise of Plate Tectonics:

Later research in the mid-20th century, especially the discovery of seafloor spreading and the theory of plate tectonics, provided the missing mechanism to explain how continents move. Plate tectonics explained the movement of continents as a result of the interaction of large, rigid plates that make up the Earth's outer layer. This theory was supported by numerous pieces of evidence, such as the magnetic striping pattern on the ocean floor and the discovery of mid-ocean ridges.

In summary, Alfred Wegener's evidence for continental drift was based on observations of matching coastlines, fossil distribution, geological formations, glacial evidence, and paleoclimate data. While his theory was initially met with skepticism, it laid the groundwork for the modern understanding of plate tectonics, which provides the mechanism for continental drift.