In the question of color, he conduces a rather thorough enquire, considering also factors of diet and health, but ultimately believes that "climate, and the influence of the soil and the temperature, together with the mode of life, have the greatest influence". Blumenbach's conclusion was, however, to proclaim all races' attribution to one single human species. Blumenbach argued that physical characteristics like skin color, cranial profile, etc., depended on environmental factors, such as solarization and diet. Like other monogenists, Blumenbach held to the "degenerative hypothesis" of racial origins. He claimed that Adam and Eve were Caucasian inhabitants of Asia, and that other races came about by degeneration from environmental factors such as the sun and poor diet. He consistently believed that the degeneration could be reversed in a proper environmental control and that all contemporary forms of man could revert to the original Caucasian race.