It seems that the enormous diversity of frogs on our planet is a direct consequence of the asteroid strike that was responsible for the dinosaur extinction. According to the newest study, the frog populations practically exploded after dinosaurs died out some 66 million years ago. Earlier studies have been showing much earlier origin of frogs, but this new study seems to contradict this.
A US-Chinese team of researchers has done major work on this topic and the results are outlined in the journal PNAS. According to the research, frogs had become one of the most diverse groups of vertebrates, with the number of described ones go as high as 6,700. However, it was fairly difficult to trace their evolutionary history. This new study shows that modern frogs have three lineages and, according to the newest evidence, all three appeared almost simultaneously at the origin point.
This impressive diversification has happened once the asteroid struck down the edge of the today’s Yucatan Peninsula in Mexico. This asteroid has released enormous amounts of energy that has set the stage for the rise of this interesting species.
The research team combined the found genetic information from frogs with additional 145 species to try and produce a sort of a family tree which is based on the various genetic relationships.
Frog fossils provide a very valuable data source for genetic research and scientists are able to trace the origins to a big expansion that happened over 66 million years ago.
According to co-author Peng Zhang, from Sun Yat-Sen University in Guangzhou, China, these results were never seen before by anyone. “We re-did the analysis using different parameter settings, but the result remained the same. I realized the signal was very strong in our data. What I saw could not be a false thing.” said Zhang. Another researcher, David Blackburn, from the Florida Museum of Natural History said: “Frogs have been around for well over 200 million years, but this study shows it wasn’t until the extinction of the dinosaurs that we had this burst of frog diversity that resulted in the vast majority of frogs we see today.”