By now you're an expert on various mechanisms of evolution, but being a good scientist, you want EVIDENCE! You've come to the right place. In this section, you'll learn about different kinds of evidence that have been used to support the idea that evolution occurs. Early evolutionary thinkers made some early observations—from geology, the fossil record, biogeography, and comparative anatomy. Evidence from these sources showed that the earth was much older than previously thought, and that the kinds and distributions of organisms had changed over time. Other kinds of evidence, such as developmental and genetic data, have come to light more recently, and provide even more overwhelming evidence that evolution is real. All the sources of evidence discussed here point to one inevitable conclusion: that all living things are related to each other. All are descended from a common ancestor, and over time, evolution shaped the diversity of organisms that populate the planet today. But don't take our word for it—check out the evidence and decide for yourself.