The world's tiniest primate has just cleared early humans of a 50,000-year-old crime.
Thanks to a new study that analyzes geogenetic patterns in mouse lemurs, we now have a better understanding of what caused (or rather, what didn't cause) the early destruction of Madagascar's forested regions. While scientists originally believed early humans were solely to blame for the increasing fragmentation of forests across the large island, the findings prove that the biogeography of Madagascar was changing long before their arrival.
So how exactly did they come to this conclusion by just analyzing mouse lemur DNA? Science writer Jason Bittel explains the nitty-gritty behind the study in the Washington Post:
"[Scientists] collected DNA samples from five mouse lemur species that inhabit various parts of Madagascar. Then, using a relatively new technology called RADseq, they sequenced each of those samples and compared them to each other to find out how closely related each mouse lemur species is, how long ago they diverged, where each species used to live geographically and whether those species still inhabit their ancestral home. With all that data in front of them, they can paint a picture of lemur populations long past — and by doing so, they give themselves a window into the evolution of different ecosystems."
What this data demonstrated was that there are several modern lemur species — like the brown mouse lemur and the Madame Berthe's mouse lemur — that are closely related despite not living anywhere near each other.
Researchers theorize that they originated from a single species tens of thousands of years ago, but have been separated over the past tens of thousands of years due to the climatological destruction of forested "bridges" that previously connected them to different parts of the island. Once cut off from each other, they began to evolve separately into the species they are today.
Although this confirms climate change wreaked havoc on the island thousands of years before humans arrived, that still doesn't exonerate us completely. Since humans set foot on the massive island 2,000 years ago, Madagascar has lost more than 90 percent of its original forest cover to slash-and-burn agriculture.