A normal or Gaussian distribution of step lengths is probably the most common
model of human movements across the landscape. For example, Ammerman and
Cavalli-Sforza’s famous “wave of advance” model for the spread of agriculture
(1979) assumes a Gaussian distribution of steps. The approach originated in
Fisher’s (1937) model for the diffusion of advantageous alleles across the land-
scape. This model is effectively a stochastic one, which would arise in the event of
a spatially random distribution of campsites. This kind of model is, of course, com-
mon for two reasons. First, the existence of random effects in natural (or cultural)
processes such as these seems innately reasonable to some investigators. Second,
Gaussian statistics have traditionally been used in modeling because they are math-
ematically tractable. The Gaussian model of step lengths can, however, be rejected
as a model of the Ju/’hoansi data set because p < 0.05 (Table 1).