Origins of modern amphibians

Article By:

Anderson, Jason S. Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada.

Last reviewed:2009

DOI:https://doi.org/10.1036/1097-8542.YB090089

The evolutionary origin of modern-day amphibians [Lissamphibia: frogs and toads (Anura), salamanders and newts (Urodela or Caudata), and the limbless caecilians (Apoda; “rubber eels”); Fig. 1] has been one of the more vexing problems confronting biologists for many years. In the past decade in particular, this issue has been contentious, with three different hypotheses offered to solve the problem. This controversy has, in turn, motivated new research from several different angles, including paleontology, anatomical- and molecular-based analyses of relationship, and molecular-based estimates of divergence timing (“molecular clocks”). The evidence has been mounting, especially in recent years, and a resolution appears to be in sight. This article briefly examines the controversy and some of the new evidence from fossils and molecular studies that is helping to establish the origins of modern amphibians.

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