refers to among-individual variation in metamorphosis: some individuals experience the typical metamorphosis as a juvenile whereas others become sexual mature and forego metamorphosis (i.
resulting from general slowing down of developmental rates in shape.
Russell (1916), for example, provides a long list of reasons to reject the biogenetic law as universal, including the existence of heterochronic processes such as paedomorphosis
This phenomenon, where a change in the developmental timing of a creature produces morphological changes is called heterochrony, and paedomorphosis
is one example of it," Abzhanov explained.
Ontogeny discombobulates phylogeny: paedomorphosis
and higher-level salamander relationships.
Characterizing the ancestors: paedomorphosis
and termite evolution, in T.
is the condition wherein an animal become sexually mature before metamorphosis, with the result being that many larval/juvenile features are retained in the adult stage of the life cycle.
Moreover, some changes are consistent with an evolutionary quirk known as paedomorphosis
, in which species retain in adulthood the youthful dimensions that their ancestors had as juveniles.
2005) viewed the occurrence of paedomorphosis
as evidence against recapitulation.
Based on the final effect of such perturbations, two basic heterochronic processes underlying organismal development can be identified: paedomorphosis
and peramorphosis (Fig.