A huge asteroid strike about 66 million years ago completely wiped out the dinosaurs from Earth, while also erasing about three-fourth of Earth’s life. The event, however, came as a big opportunity for Frogs to grow their population and become one of the most diverse vertebrates on Earth. This is the finding of a new study recently published in the Proceedings of the National Academy of Sciences.
Frog first appeared about 200 million years ago
Frogs are believed to have first appeared in the world about 200 million years ago. Today, about 6,700 frog species exist on Earth, but the study suggests that only 10 types of frogs species had most likely survived the Mass Extinction Event, and of these, only three species could diversify and grow their population in the world.
These creatures survived the asteroid strike probably because they were able to stay underground for long periods of time. Today, about 90 percent of the modern frogs found on Earth trace their roots back to these three frog species. They increased their numbers like an “explosion” and thrived in the space left vacant by other creatures, especially dinosaurs.
Three frog species thrived on Earth after mass extinction event
In this study, researchers from the United States and China compiled and evaluated the largest ever frog genetic data. Researchers took genetic samples from 156 frog species, and combined this data with previous data of 145 more species. They examined variations in 95 genes to analyze how different frog species relate to each another.
Fossil records of frogs were also examined to determine how and when different frog species diverged from each other. According to researchers, they found evidence of three population explosions of frog species—Hyloidea, Natatanura and Microhylidae—after mass extinction event on Earth. Interestingly, these population explosions occurred on different continents.
While Hyloidea species thrived in South America region, the other two species—Natatanura and Microhylidae—prospered in Africa.
David Wake, the study co-author from the University of California, suggests that mass extinction events do have some positive aspects as they provide “ecological opportunity” for new things to happen.
Similar to what happened with frogs, the mass extinction event is also known to have helped a few bird species explode in diversity and allow them to be among the prominent groups of land animals.
After the extinction of dinosaurs, the frogs had ample room for evolution. They learned how to climb into trees to find shelter. They even started laying eggs on the ground, thus skipping the tadpole phase. Today, this is a standard practice for almost fifty percent of the all frog species.