Scientists have discovered signs of a frog that has been listed as extinct and unobserved since 1968. In this, the biologists were helped by an innovative technique to detect endangered and endangered species in two regions of Brazil. The frog Megaelosia bocainensis was among the seven species found. The results were published in the journal Molecular Ecology.
In the study, scientists collected and tested environmental DNA – eDNA – from the biodiverse coastal forests of the Atlantic and the Cerrado meadows in Brazil.
The eDNA method offers a survey method that can confirm the presence of species not detected by traditional methods, helping environmental scientists re-evaluate the presence of species in the environment that are endangered or have not been observed for years.
After extensive research to identify species at different levels of threat in these regions of Brazil, the researchers used eDNA to find 30 target amphibian species in six locations where frogs are known to have previously lived.
“The little bits of DNA in the environment don’t tell us how many individuals exist and whether they are healthy, but they tell us that the species is still present,” explains senior study author Kelly Zamudio, Professor Goldwyn Smith. Ecology and Evolutionary Biology at the College of Arts and Sciences.
Living organisms leave traces of DNA in soil, water and air. Scientists are now increasingly using highly sensitive sampling techniques for eDNA detection in order to conserve species.
The researchers took water samples. Back in the lab, they extracted the DNA, genetically sequenced it, and weeded out genetic material from humans, pigs, chickens, and other organisms until they could isolate all of the frog’s DNA.
The identification of M. bocainensis required a lot of work: the species disappeared long ago, and there were no tissues from which DNA could be extracted for comparison with eDNA. But the researchers had sequences for all sister species of the genus Megaelosia, and they knew the ranges of its related species.