The observed distribution fit the expected distribution for a single dominant macromutation
segregating in a backcross population (P = 0.84).
Dhumal, "Induced macromutations
in horsegram [Macrotyloma uniflorum (Lam.) Verdc]," Legume Research, vol.
Especially, the effect of macromutations (Jablonski, 2000), complex mutations involving concurrent alteration of numerous characteristics of species, deserves attention for the domain of evolution of organizations.
Long jumps, forced macromutations might prove very effective on rugged landscapes, where many fitness peaks exist, though they become a weak strategy as the complexity (diversity and numbers) increases.
Many mechanisms have been proposed to explain these shifts, most prominently Wright's (1977) shifting balance; others have included Fisher's (1958) idea that individual fitnesses change frequently and Goldschmidt's (1940) macromutations
. Here I suggest a modification of Wright's idea that applies when adaptive landscapes are defined with respect to phenotypes - that changes in the phenotypic variance resulting from drift allow transition to occur.
Another theory suggests that macromutations
are responsible for creating morphological diversity and are responsible for the rapid changes seen in the fossil record (Stanley 1979; Gould 1980; Rachootin and Thomson 1981).