What is an hypothesis that has been tested many times and is supported by evidence over a long period of time?

One well-tested hypothesis is the theory of evolution by natural selection, proposed by Charles Darwin. This hypothesis suggests that species evolve over time through the process of natural selection, where advantageous traits become more common in a population. Extensive evidence from various fields, including genetics, Paleontology, and comparative anatomy, has consistently supported this theory for over 150 years, demonstrating how species adapt to their environments and giving rise to the diversity of life we see today.