HETEROCHRONY
| Collection | International Encyclopedia of Systems and Cybernetics |
|---|---|
| Year | 2004 |
| Vol. (num.) | 2(1) |
| ID | ◀ 1519 ▶ |
| Object type | General information, Methodology or model |
A differential Template:Ency term and/or Template:Ency term in a living Template:Ency term .
Heterochrony can be understood in two different Template:Ency term :
1) The differential Template:Ency term of different Template:Ency term in a living being. For example, in the human species, the head grows more than the rest of the body at the embryonic and fetal stages, but this trend is reversed after the birth.
2) The different rate of embryonic development in different species. The German biologist Ernest Template:Ency person (1834-1919), comparing embryos of different species during their development, came to the conclusion that, at least in vertebrates, different growth rates produced very different animals from quite similar embryos. His idea that “Template:Ency term recapitulates Template:Ency term ” proved later on to be a too simple evolutive principle. (Ken McTemplate:Ency person, 1999, p.1-4)
In fact, Template:Ency term , i.e. the conservation in adults of embryonic or juvenile biological Template:Ency term , appears to be a truer evolutive Template:Ency term . It is also of course related with heterochrony.