Among Dunnell's contribution to archaeology was the recognition of the role the theory of biological evolution as a means of explaining cultural phenomena.
[9] In addition, he argued that "cultural evolution" which has its roots in 19th Century social scientists such as Lewis Henry Morgan and Herbert Spencer is distinct from "scientific evolution" which Darwinian in character.
Cultural evolution is vitalistic and assumes a direction to the nature of change (i.e., progress).
While advocating "scientific evolution" as the basis for anthropological theory, Dunnell argued that the use of a strictly biological model was insufficient to explain cultural variability.
He argued that a more comprehensive version of evolutionary theory is needed that considered cultural inheritance as an additional means of the transmission of variability between individuals.