Of these processes, we found neoteny (decreased developmental rate in descendant), progenesis (earlier offset), and acceleration (increased rate) to be more commonly reported than hypermorphosis (delayed offset) or predisplacement (earlier onset).
Thus, it was suggested that populations of subalpine hay meadows are the peramorphic variants derived from populations of alpine grassland by predisplacement in vegetative gr owth and that populations of subalpine limestone grassland are peramorphic variants derived from populations of alpine grassland by hypermorphosis in vegetative growth.
Therefore, a joint effect of hypermorphosis, neoteny, and postdisplacement has resulted in the evolution of small homostylous flowers in A.
These mutants cause dramatic morphological changes by different types of heterochronic processes, including neoteny, progenesis, acceleration, and hypermorphosis.
Of the six pure classic heterochronic processes, we found neoteny (decreased developmental rate in descendant), progenesis (earlier offset), and acceleration (increased rate) to be more commonly reported than hypermorphosis (delayed offset) or predisplacement (earlier onset).
the controversy about the relative role of neoteny or hypermorphosis in human evolution (McKinney and McNamara 1991)].
Therefore, in a particular case, the question is not whether there is, for example, either neoteny or hypermorphosis, but what the relative importance of these processes is for the observed evolutionary change.
In a bivariate allometric plot of a trait against size, an extension of the ancestral allometric trajectory to larger sizes in a descendant species is called "allometric hypermorphosis," whereas termination of growth at smaller sizes is "allometric progenesis.
For neoteny and acceleration, the expected patterns result only if the trait alone is affected, and for progenesis and hypermorphosis if both the trait and size are affected by the heterochronic change.
These do not represent dimensional allometry but may be the result of developmental hypermorphosis
in which a developmental growth pattern is played out at the same rate (or rate of increase) over a lengthened period of time (either the entire lifespan or just the juvenile stage) (Gould, 1977).
predisplacement, postdisplacement, hypermorphosis
, progenesis sensu McKinney & McNamara, 1991) cannot be ruled out.