An animal that never olds : a unique case of Paedomorphic Axolotl (Ambystoma mexicanum)
Almost everyone wishes to be forever young. Scientist had exerted a great deal of effort in finding the so called “the secret of youth” assorting in modelling of molecules that may retain youthfulness up to the very widely held stem cell research. As humans are engaged with this quandary, an amphibian in a name of axolotl are of free from distress with such predicaments - hence they had the secret of youth, but the drawback is, they are deprived of the refinement of maturity. Fair enough so I say.!
Paedomorphosis is the retention of ancestral juvenile characters by adult stages of descendants. Paedomorphosis has occurred when reproduction is seen in what was ancestrally a juvenile morphological stage. This can be the result of neoteny or progenesis.
In neoteny, the physiological (or somatic) development of an animal or organism is slowed or delayed while in Progenesis, it involves the retention of ancestral juvenile characters by adult stages of descendants due to an acceleration of the sexual maturation and thus is often regarded as a fast evolutionary process.
Paedomorphosis may have two important evolutionary effects:
• It may stop recapitulation that occurs during the development of the organism.
• It may be important in the origin of higher taxa. The first component of the argument is empirical. For many large groups of animals, the adults appear to resemble an early developmental stage of a possible ancestor.
The axolotl is a famous example of paedomorphosis, retaining in maturity the feathery gills that related species lose in infancy. In fact, it becomes sexually mature in this state. This adaptation, known as neoteny, is often viewed as a backward step in evolution because it prevents the axolotl from living on land, and as a result, it can’t colonize new habitats. Axolotls are also famous for their fabulous regeneration ability. This regeneration occurs via the formation of a “bud” at the end of the damaged appendage, followed by growth of the new foot. Entire limbs can be regenerated and even portions of the brain and spine. How cool!..
(Photo credit: Axolotl.org)?