Thomas (Tom) Cavalier-Smith, FRS, FRSC, NERC Professorial Fellow (born 21 October 1942), is a Professor of Evolutionary Biology in the Department of Zoology, at the University of Oxford.[1] His research has led to discovery of a number of unicellular organisms (protists) and definition of taxonomic positions, such as introduction of the kingdom Chromista, and other groups including Chromalveolata, Opisthokonta, Rhizaria, and Excavata. He is well known for his series of classification system of all organisms.