“... reflecting on the mutual affinities of organized beings, on their embryological relationships, on their geographical distribution, on geological succession and on other similar facts, he could come to the conclusion that each species does not was independently created, but descended, like varieties, from other species." (Charles Darwin. The Origin of Species)Evidence for natural selectionDarwin's theory of evolution by natural selection is one of the best documented theories in the history of science, supported by evidence found in studies of paleontology, biogeography, comparative embryology, comparative anatomy and biochemistry. Paleontology is the study of fossils. Fossils are remains or traces of long-dead animals and plants that become trapped in sediment, ice, or amber that allows for their preservation. They provide evidence of how living things have evolved over time on earth. Two aspects of the fossil record are very important for supporting evolutionary ideas: older fossils contain simple life forms, while younger fossils contain much more complex life forms.