Final answer:
Charles Darwin used evidence from fossils, biogeography, comparative anatomy, and embryology to support his theory of evolution by natural selection.
Step-by-step explanation:
When Charles Darwin developed the theory of evolution by natural selection, he utilized a variety of evidence to support his groundbreaking ideas. Among the key types of evidence he used were:
- Fossil Evidence: Darwin examined fossils that showed changes in species over long periods of time, suggesting a gradual process of evolution. The fossil record showed a pattern of earlier species resembling newer ones, pointing to a lineage of descent.
- Biogeography: His observations on the Galápagos Islands revealed that animals were well-adapted to their specific environments, indicating that species evolved differently depending on their location and surroundings.
- Comparative Anatomy: Darwin noted similarities in the structures of different species (e.g. mammalian limbs) that function differently but have a common ancestral origin.
- Embryology: He noticed embryonic similarities across different species, lending evidence to a common descent.
It is important to clarify that Darwin's contribution was specifically the mechanism of natural selection, which is the process by which advantageous traits become more common in a population because they increase an organism's chances of survival and reproduction. While evolution describes the broad process of change in life forms over time, natural selection is the mechanism of how those changes occur and spread in a population.
Impact of Natural Selection
- Natural selection shaped the traits of organisms over generations. For example, Darwin's theory can explain the evolution of the Galápagos tortoises, which have saddle-shaped shells. This adaptation likely developed in response to the need to reach higher vegetation on the islands with scarce low-lying food sources, favoring individuals with longer necks and modified shells.