Volume 65, Issue 5, pages 1283–1296, May 2011
RE-EVOLUTION OF LOST MANDIBULAR TEETH IN FROGS AFTER MORE THAN 200 MILLION YEARS, AND RE-EVALUATING DOLLO'S LAW
John J. Wiens
Article first published online: 27 JAN 2011
© 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.
Keywords: Amphibians; developmental constraint; Dollo's law; morphology; phylogeny
Dollo's law states that structures that are evolutionarily lost will not be regained. Recent phylogenetic studies have revealed several potential examples in which Dollo's law seems to be violated, where lost structures appear to have been regained over evolutionary time. However, these examples have recently been questioned and suggested to be methodological artifacts. In this article, I document a striking and incontrovertible phylogenetic example of the re-evolution of a lost, complex structure: mandibular teeth in the frog genus Gastrotheca. I use a time-calibrated phylogeny for 170 amphibian species to show that mandibular teeth were lost in the ancestor of modern frogs at least 230 million years ago (Mya) and have been regained in the last ∼5–17 My. I review recent studies on trait re-evolution and show that this long period of trait absence prior to re-acquisition is largely unprecedented. I also argue that there are several methodological issues that may cause trait re-evolution to be hardest to detect under those conditions when it is most likely to occur, leading to erroneous failures to reject Dollo's law. Finally, I discuss a mechanism that may facilitate trait re-evolution, and the evolution of mandibular teeth in frogs as an example of developmental constraint.
NOTA DESTE BLOGGER:
O bom do paradigma evolucionista é que qualquer que seja a evidência, ela sempre será a favor de Darwin, o homem que teve a maior ideia que toda a humanidade já teve. Na ausência de dentes, a teoria da evolução de Darwin explica. Na volta dos dentes, a teoria da evolução de Darwin explica. Explica tudo, até mal olhado...
Essa flexibilidade heurística, mesmo que fira a lógica, sempre conta a favor de Darwin. Aprendi na universidade, não sei se ainda ensinam isso, que uma teoria científica que explica tudo não explica nada. NOTA BENE: NÃO EXPLICA NADA!!!