Identify personal experiences that contributed to Darwin’s thinking about evolution.
Identification of fossils: Fossils provided that slow and continuous actions could result in the evolution of organisms.
Population theory by Malthus and Lyell’s uniformitarian thoery has a great impact on Darwin’s knowledge about evolution.
Observations on Galapagos Islands: Several turtle species are endemic to Galapagos Islands. He wondered how they could reach the islands. He observed beak morphology adaptations in fiches which supported the theory of adaptation and natural selection.