Where Did Bats Originate? Huge Genetic Study May Have Settled the Longstanding Debate and Rewritten the Creatures' Evolutionary Tree

With 1,500 species spread across every continent except Antarctica, they make up about one-fifth of all mammal species and rank as the second most diverse group of mammals, after rodents. They’re the only mammals that can truly fly, they use echolocation to “see” in the dark, and they’re highly resistant to disease, carrying a variety of fatal viruses while seemingly never getting sick themselves. Yet the origins of bats have remained mysterious—until now.

The airborne mammals likely arose 65 million years ago in Europe, rather than in Africa, North America or Asia, as had previously been suggested, according to a study published September 23 in the journal Nature. The work provides a new evolutionary family tree for bats, shedding light on the various species’ evolutionary histories and relationships with one another. What’s more, the study represents largest-ever analysis of bat genomes, or complete sets of genetic instructions, and fossils.

And scientists say it’s just the beginning. The paper lays the groundwork for future research into how bats evolved unique adaptations like echolocation, flight and disease resistance. Andrews in Scotland, tells Live Science’s Sascha Pare.

They also compared physical characteristics across 65 species, including 44 bat fossils and members of most extant bat families. The team—made up of more than 130 scientists from around the world—used the combined data to chart relationships between different bat groups, estimate when their evolutionary lineages diverged and investigate where bats originated and how they spread around the globe. After the animals arose in Europe, the evidence suggests they ventured into Africa, before expanding to Asia, the Americas and Australia.

The results also add to the debate over whether echolocation or flight evolved first in bats. A prominent study published in 2008 suggested that flight came first. But the new research, which is based on a bigger dataset, muddies that conclusion by pushing back the timeline on echolocation.

Moving forward, the project’s findings could help support conservation efforts, as bats face threats like habitat loss, climate change, collisions with windmill turbines and disease. One of the most pressing examples is white-nose syndrome, a fatal fungal disease that infects bats that hibernate each winter. Discovered in 2006, the disease has since spread across the United States and Canada and killed millions of bats.