What types of evidence did Darwin use to support his theory of change over time ?

 Charles Darwin used a variety of types of evidence to support his theory of evolution by natural selection and the concept of change over time. Some of the key types of evidence that Darwin presented in his seminal work "On the Origin of Species" (1859) included:

1. Fossil Evidence: Darwin examined the fossil record and observed that fossils showed a progression from simpler to more complex forms. This supported the idea that life has changed over time and that different species have followed different evolutionary paths.

2. Geographical Distribution: Darwin studied the geographical distribution of species, especially on his voyage on the HMS Beagle. He noted that different but closely related species often occupied different habitats within a region, or similar habitats in different parts of the world. Island biogeography, including findings from the Galapagos Islands, was especially important, as he observed that species on islands were similar to but distinct from those on the nearest continents.

3. Morphological Homologies: Darwin observed similarities in the structure of different organisms (e.g., the limbs of humans, whales, birds, and dogs) that he interpreted as evidence of common ancestry. These structures are known as homologous structures and suggested that varied animals had similar origins with subsequent modifications.

4. Embryological Evidence: He noticed that embryos of distinct species often resemble each other, supporting the idea that they share common ancestors.

5. Artificial Selection: Darwin also pointed to the results of selective breeding by humans, where people have been able to create dramatic changes in domesticated plants and animals over short time periods by selecting for desirable traits. This provided an analogy for how natural selection could operate over longer periods.

6. Vestigial Structures: Darwin examined organisms with vestigial structures, parts of the body that seem to be remnants from ancestors. These structures, like the human tailbone or whale pelvic bones, made little sense unless the species had changed over time from an ancestor in which the structure was functional.