Friday, April 25, 2008

Better intuitions about biology: Paedomorphosis

This charming little salamander doesn't look much like other salamanders you've seen! That's because this species of salamander exhibits a condition called paedomorphosis, a condition in which a species retains certain juvenile characteristics of their ancestors through adulthood.

It is an axolotl, and is closely related to the tiger salamander.

While these two species look awfully different in adulthood, it can be difficult to tell a larval tiger salamander and an axolotl apart.

Scientists may administer hormone treatments to axolotls that cause them to metamorphose, losing their juvenile features. These artificially metamorphosed specimens look like adult tiger salamanders.

While the weird cuteness of an axolotl is enough to make it interesting by itself, it's example of paedomorphosis shows us that a small genetic change can result in species which look and live very differently from their closest ancestors.

1 comment:

Ashley said...

I've always loved axolotls.. ever since I first read the dictionary.