Frogs re-evolve teeth, claims a scientist in an article in the journal Evolution 27 January 2011 DOI:10.1111/j.1558-5646.2011.01221.x, and BBC Earth News 31 January 2011. A tree dwelling frog named Gastrotheca guentheri is the only known frog with teeth on both upper and lower jaws. Other frogs do not have teeth in their lower jaws, and it is assumed that the ancestor of modern frogs lost them millions of years ago. According to evolutionary biologists, once complex structures like teeth are lost in evolution they cannot re-evolve. This concept is called “Dollo’s Law”

John Wiens, Department of Ecology and Evolution, Stony Brook University, claims he has found an exception to Dollo’s Law. He explained: “I combined data from fossils and DNA sequences with new statistical methods and showed that frogs lost their teeth on the lower jaw more than 230 million years ago, but that they re-appeared in G. guentheri within the past 20 million years.” He went on to say: “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”.

BBC

Editorial Comment: The actual observational data we have is that Gastrotheca guentheri has lower teeth and others don’t. No-one has observed a toothless Gastrotheca guentheri, and no-one has observed a toothless frog of any kind gain any teeth. It is possible that other frogs once had teeth but lost them. It is even possible that other frogs still have the genetic information for lower teeth, but are perhaps missing a chemical signal that stimulates them to grow, just as the amphibian Axolotls can grow up, but in their original environment which lacked Iodine their growth glands could not function, so they didn’t. Easy to prove – buy one and put no iodine in its tank. They simply mature without leaving the tadpole stage.

Back to the frogs, either way, loss of teeth is degeneration, not evolution.

We also wonder why evolutionists believe so firmly in “Dollo’s Law”. If they can believe complex structures like teeth evolved by chance random processes from nothing in the first place, so why can’t they believe complex structures can evolve again by the same processes? We suppose it takes so much faith to believe living things evolved once, they must not have enough left to believe living things evolved twice. (Ref. amphibians, devolution)

Evidence News 16 March 2011