It's important to note that scientists don't "prove" evolution in the same way we might prove a mathematical theorem. Evolution is a scientific theory, meaning it is a well-substantiated explanation of some aspect of the natural world that can incorporate facts, laws, inferences, and tested hypotheses. It's supported by a vast amount of evidence, and the evidence is constantly growing and becoming more refined.

Here are three examples of the types of evidence that scientists use to support the theory of evolution:

1. Fossil Record: Fossils provide a direct record of past life forms and their changes over time. We see clear transitions in the fossil record, showing how organisms evolved from simpler to more complex forms. For example, the transition from land mammals to whales can be traced through fossils with progressively more aquatic adaptations.

2. Comparative Anatomy: Similarities in the anatomy of different organisms, especially those that share a common ancestor, provide strong evidence for evolution. For instance, the forelimbs of humans, bats, whales, and crocodiles have very similar bone structures, suggesting a common evolutionary origin. This is called homologous structures.

3. DNA Evidence: Molecular biology has provided powerful evidence for evolution. The similarity of DNA sequences between different species reflects their evolutionary relationships. For example, humans share around 98.8% of their DNA with chimpanzees, indicating a close evolutionary relationship. This genetic similarity supports the idea that all life on Earth shares a common ancestor.

It's important to remember that this is just a small sample of the evidence supporting the theory of evolution. There are many other lines of evidence, such as biogeography, embryology, and artificial selection, that contribute to our understanding of how life has evolved on Earth.