He had a degree in theology and firmly believed in creation until he started considering the enormous diversity of life that he encountered on his voyage on the H.M.S. Beagle. 1. descent with modification from common ancestors in other words, look at history of the traits Darwin provided abundant evidence and examples of this, since then we have accumulated hundreds of thousands of examples from comparative anatomy to molecular biology 2. Since Darwin's time we have developed an understanding of heritability, identified examples of natural selection, and identified other causes of evolution besides natural selection. The basic bones have been highly modified to serve different functions but the bones are shared across many species. Fetal anteaters have teeth but the adults do not.
Terrestrial amphibians pass through a stage that resembles aquatic larvae while still in the egg.
Your goosebumps likely provided enhanced insulation when your ancestors were much hairier. Dandelions produce flowers but the seeds develop without fertilization by pollen. Some primitive moths still have small jaws even though they are not used. There are many examples of marsupials in Australia that are similar to placental mammals from the other continents. For natural selection to occur, three rules must be in place.