A new study carried out by scientists from Chinese and American researchers suggests that frogs were able increase their populations after dinosaurs got extinct from the planet about 66 million years ago when an asteroid slammed into Earth.
“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,” said study co-author David Blackburn, associate curator of amphibians and reptiles at the Florida Museum of Natural History.
“This finding was totally unexpected.”
According to researchers, only 10 types of frogs probably survived the mass extinction event. Of these types, only three types of frogs were then able diversify and on increase their population on Earth. Today, about 6,700 frog species exist in the world and of these about 88 percent trace their roots back to those three lineages.
In this study, researchers compiled a large set of frog genetic data. They took genetic samples from 156 frog species. This data was then combined with previously published data on 145 more species. Researchers also analyzed fossil records of frogs to determine the period when different kinds of frogs diverged from one another.
Evidence was found of three explosions of new frog species, on different continents. Two of the three surviving lineages—Microhylidae and Natatanura—thrived in Africa, while the third, Hyloidea, spread in South America.
“These frogs made it through on luck, perhaps because they were either underground or could stay underground for long periods of time,” said co-author David Wake of the University of California.
“This certainly draws renewed attention to the positive aspects of mass extinctions: They provide ecological opportunity for new things.”
The detailed findings of the study have been published in the journal Proceedings of the National Academy of Sciences.