A distinction first made by Wilhelm L. Johannsen (1857-1927) in 1909. Genotype is the genetic constitution of a cell or individual. When if refers to the whole organism, the term is sometimes exchanged with genome. Phenotype is the organism’s characters (structural and functional) determined by the combined influences of its genetic constitution and environment. Phenome is sometimes used when reference is made to the whole organism. According to the evolutionary biologist Theodosius Dobzhansky (1900-1975), a phenotype has a much broader connotation, namely, that it is “… the total of everything that can be observed or inferred about an individual.” [Dobzhansky, T. (1962). Mankind evolving. New Haven, CT: Yale University Press, pp. 41-42]. Thus, it includes both external appearance and internal anatomy and physiology, as well as a person’s cognitive processes and interaction with events, objects and people. It changes over time, and depends to a large extent on the environmental circumstances that a person has encountered.
See Behavioral phenotype syndromes, Character, Cultural evolution and biological evolution, Epigenetics, Forward genetics, Function, Gene, Gene traps, Genome, Inclusive fitness, Motor noise, Mutant, Polygenes, Trait