Darwin’s Finches, Part Two: Speciation in Fanged Frogs in Sulawesi

Photo by Rafe M. Brown.

In ecology, there are many factors that contribute to the number of species in an area. One idea is that the more space there is, the more opportunity for more species to exist. But Ben Evans and scientists from McMaster University (Hamilton, Ontario) have found an anomaly; nine unrecorded species and the rapid adaptation of new fanged frogs have been recorded in the small island of Sulawesi.

The team found these fanged frogs, named for their tooth-like protrusions, in similar species numbers to that of the large Philippine archipelago to the north.

The reason why a small island like Sulawesi and larger islands like the Philippines have similar species numbers is due to competition. In the Philippines, these fanged frogs have much more competition from other frog species. The frogs that made the hop over to Sulawesi had a new niche with different predators and elements to cope with, providing an opportunity for speciation to occur.

Evans has been studying the frogs since 2000. It, like Darwin’s finches, is a remarkable showcase of adaptation within a short timeframe (in evolutionary time, that is). This adaptive radiation occurred in less than 15 million years.

“With the frogs, we found that they have made a number of adaptations… all of which matched the demands of their particular ecological niches,” said Evans in a press release.

Examples of adaptive radiation in fanged frogs include larger body size (about twice the size, in order to deal with fast-moving waters) and laying jelly-like egg capsule on tree leaves.

This great discovery comes with more possibilities. With this research, pockets of diversity have been found all across the island. This will undoubtedly assist in prioritizing conservation efforts (if applied correctly).

The Research can be found in The American Journalist.