Richard B. Root

Richard Bruce "Dick" Root (7 September 1936 – 22 January 2013) was a professor of evolutionary biology, ecology and entomology. He was an important contributor to the field of ecology, and is best known for introducing the concept of the ecological “guild”. This concept is found in his doctoral research paper focused on defining the ecological niche and comparing the niche dimensions of the blue-grey gnatcatcher with other insectivorous bird species. Provided by Wikipedia