The main argument in Derwent Whittlesey’s article “Sequence “occupance” is that the “human “occupance” is like the “biotic phenomena” which carries “…the seed of its own transformation” within itself (p. 162). Therefore, sequent “occupance” is the process in which a landscape is gradually transformed by a succession of occupying populations, each of which modifies the landscape left by the previous group.
He justifies his arguments with some examples: “farmer’s encroachment in the virgin soil” that they plow, grow, and harvest, or, in the extreme case farmers leaving the land “…abandoned and converted into pasture or forest”; human attachment towards “urban life” and ultimately shifting the urban area “…to a zone some distant from the center” and beginning a new urbanization; and “…political unification of a large and diverse area under a single system of government” which under “many laws of hardships” outburst into a smaller “unit” (p. 162). A very good example of sequent “occupance” is New England, where Whittlesey forecasts that the human “occupance” in New England will be reversed and “occupance” by forest will be dominant “…at the will of non-resident owners for wood-pulp or for lumber” (p. 163). He argues that “each generation of human “occupance” is linked to its forbear and to its offspring, and each exhibits an individuality expressive of mutations in some elements of its natural and cultural characteristics” and therefore the transformation of life history is “inevitable” from stage to stage (p. 163). This justifies his argument that the sequent “occupance” is “genetically” influenced.
He admits sequent “occupance” is an “intricate problem”—nevertheless, “simplified with the chronological study of the natural and cultural landscape” and he concludes suggesting “classification” of sequence “occupance” should be made on the basis of chronology which is “…structurally firm and homogeneous” (p. 165). For Whittlesey, the important thing was that the human/sequent “occupance” was similar to the biotic phenomena which establish the genetic relation with each stage in terms of the predecessor.