However, both Darwin and Alfred Russel Wallace, the co-founders of the theory, and all subsequent biologists depend primarily on observations of living organisms; Darwin concentrated largely on the breeding of domesticated animals whereas Wallace started from the biogeographical distribution of species in the Amazon and Malay Archipelago.
Porén, tanto Darwin coma Alfred Russel Wallace, os cofundadores da teoría, e todos os seguintes biólogos dependen nos seus traballos principalmente da observación de organismos vivos; Darwin concentrouse en gran medida na crianza de animais domesticados, mentres que Wallace partiu da distribución bioxeográfica das especies no río Amazonas e no arquipélago Malaio.