Of the many after-effects of dinosaur extinction, probably the most surprising one was the flourishing of frogs. Frogs have survived and managed to thrive during the mass extinction about 66 million years ago that destroyed three quarters of life on earth, altered ecosystems, broke continents and, more significantly, completely wiped out dinosaurs.
The huge diversity in frogs as a species has always been of great interest to researchers. A new study that was conducted by American and Chinese biologists and was published in the journal Proceedings of the National Academy of Sciences seeks to create a new evolutionary tree for frogs. Calling the finding completely unexpected, co-author David Blackburn, associate curator of amphibians and reptiles at the Florida Museum of Natural History on the University of Florida campus, says, "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."
This study explains the evolution, pace, and factors contributing to the evolution of frogs. Researchers from Sun Yat-Sen University, the Universty of Texas, and the University of California worked with a dataset seven times larger than used in previous studies to create a phylogeny or evolutionary tree. Previously published genetic data on 145 species of frogs was combined with a core set of 95 nuclear genes from another 156 species to create this new evolutionary tree. A new timeline of frog evolution has been generated based on this evolutionary tree that represents 55 known families of frogs.
Many species of frogs today are facing the threat of extinction due to increase in the population of humans, loss of habitat, and changes in the climate. This only goes to show that humans are creating conditions so harsh that even resilient frogs who survived mass extinction in the past are in danger.
Journal reference: Proceedings of the National Academy of Sciences