Geography: the study of the physical features of the earth and its atmosphere, and of human activity as it affects and is affected by these, including the distribution of populations and resources and political and economic activities. Ethnology: the study of the characteristics of different peoples and the differences and relationships between them. Geology: the science which deals with the physical structure and substance of the earth, their history, and the processes which act on them. Ecology: the branch of biology that deals with the relations of organisms to one another and to their physical surroundings.