1.
larva of a Fire Salamander
1. The
(Salamandra salamandra) and terrestrial
form of an Eastern Tiger Salamander
(Ambystoma tigrinum) demonstrate the
typical morphological changes that
normally occur upon metamorphosis.
Images by Eric Isselee and James DeBoer.
Giant Salamander (Andrias
2. Chinese
davidianus). Image by Tristan Tan.
Hellbender (Cryptobranchus
3. Eastern
alleganiensis alleganiensis).
Hellbender foraging for crayfish.
4. Eastern
Images by Jay Ondreivcka.
while attaining sexual maturity in the larval form
(something akin to a tadpole being able to reproduce
without changing into a frog).
Neoteny has since been associated with human evolution,
in that we retain characteristics typical of immature
primates, such as a flat face, large head and relatively
short limbs. Sexual selection is speculated to be responsi-
ble. Another illustration of this phenomenon is based upon
the human predilection for ‘cute’ pets, resulting in the
selection amongst domestic dogs, for example, of puppy-
2.
like traits such as large eyes, floppy ears and smaller
stature.
Neoteny has been documented amongst birds, frogs,
insects and crustaceans, as well as many other
domesticated animals, but is common (having been
recorded in all families) and arguably most noticeable
amongst salamanders, because of the extensive and
conspicuous changes normally associated with
metamorphosis.