Neoteny
Neoteny, also called
juvenilization, is one of the two ways by which paedomorphism can arise.
Paedomorphism or
paedomorphosis is the retention by adults of traits previously seen only in the young, and is a subject studied in the field of developmental biology. In neoteny, the physiological development of an organism is slowed or delayed. In contrast, in
progenesis, sexual development occurs faster. Both processes result in paedomorphism, a type of heterochrony. Ultimately this process results in the retention, in the adults of a species, of juvenile physical characteristics well into maturity and pedogenesis, the reproduction in a neotenized state. Neoteny is one of three dimensions of heterochrony, or the change in timing of developmental events: acceleration vs. neoteny, hypermorphosis vs. progenesis, and predisplacement vs. postdisplacement. The word
neoteny is borrowed from the German
Neotenie, the latter constructed from the Greek νέος and τείνειν. The adjective form of the word is either "neotenic" or "neotenous".