Tree frogs belonging to the genus Gastrotheca are a curious group indeed.  Known as marsupial frogs, they carry their eggs in pouches on their backs until the tadpoles hatch out. 

However, it’s not their marsupial traits that have evolutionary scientists all a buzz.  In a recent report one member of the marsupial genus Gastrotheca guentheri is believed to have re-evolved teeth in the lower jaw.  The scientists studied the fossil record and DNA sequences using some of the latest statistical tools.  According to their results, this particular marsupial frog lost its lower teeth over 230 million years ago and then re-evolved them back in the last 20 million years. 

Evolutionists have long believed that once a trait has been lost for a significant length of time, such as the 200 million years in this case, that it could never be re-acquired.  This is known as Dollo’s Law.  However this new analysis is now causing them to re-think this once established law, as on of the researchers, Dr. Wiens said: The loss of mandibular teeth in the ancestor of modern frogs and their re-appearance in G. guentheri provides very strong evidence for the controversial idea that complex anatomical traits that are evolutionarily lost can re-evolve, even after being absent for hundreds of millions of years.

Some of the researchers believe that since the frogs always had teeth in the upper jaw that they still carried the traits for developing teeth and for some reason these traits somehow re-evolved in the lower jaw.  Dr. Wiens says that this re-evolution of the lower jaw teeth could be a loophole in Dollo’s Law. 

Since part of this study was based upon fossil evidence, I was curious what fossil data they were referring to as the basis for their study.  From everything I can find, Gastrotheca guentheri has never been identified in fossil form.  Several members of the larger group Hylidae (tree frogs) have been identified in the fossil record, but none of them are Gastrotheca guentheri.  If in fact this is so, then the study is flawed from the very beginning because they base their findings on other species and not on the one they are citing as having re-evolved the lower teeth. 

Personally, I find this kind of science to be dubious and highly questionable.  After all, how can they say that this species of tree frog re-evolved teeth or anything else when they have no record of what it was originally like to begin with?  However, we should not be that surprised that they make such unfounded and erroneous claims as this when they start with the unfounded and erroneous belief in millions of years and evolution. 

From a creationist perspective, I would tend to conclude that Gastrotheca guentheri contained the necessary genetic coding for teeth in the lower jaw from the very beginning.


Davies, Ella, Frogs re-evolved lost lower teeth, BBC News, Jan. 31, 2011.

Continue Reading on