In the fading light over the Congo River, thousands of hammer-headed fruit bats launch from their roosts, their box-shaped snouts honking across the northern forests of Congo-Brazzaville. For years, scientists in spacesuit-like protective gear have worked through these nights, swabbing bats for DNA. Those samples, combined with genomic data from across the globe, have just upended a century of assumptions: bats did not arise in Africa, Asia, or the Americas. They began in Europe.
A Honking Sky Over the Congo
The fieldwork is gruelling. Researchers with the Wildlife Conservation Society have spent evenings deep in the forest capturing Hypsignathus monstrosus — the hammer-headed fruit bat — to collect the genetic material that would help anchor a massive phylogenetic tree. Sarah Olson, director of health research at WCS and a co-author of the new study, describes the bats as “super amazing” on a scale of amazing to amazing. Their honking choruses, their bizarre morphology, their viral resilience — all of it now reads differently in light of what the data shows.
The European Origin Story
Published today in Nature, the study represents the largest effort of its kind. More than 130 researchers from the Bat1K consortium analysed 103 bat genomes spanning 21 families, cross-referenced with 44 fossil specimens — mostly teeth — unearthed from sites worldwide. The conclusion is unambiguous. The common ancestor of all living bats lived in Europe roughly 65 million years ago, shortly after the asteroid that ended the dinosaurs. From there, early bats dispersed into Africa, then radiated across Asia, the Americas, and Australia.
Echolocation, that defining superpower, evolved at the same deep node. Flight and sonar arrived together, a dual innovation that allowed bats to conquer the night sky before any other mammal. The finding rewrites the mammalian family tree and validates the Bat1K project’s founding ambition: to sequence every one of the 1,500 known bat species.
A Code Book for Human Medicine
The evolutionary insights are only half the story. Bats are reservoirs for Ebola, Nipah, Marburg — yet they rarely fall ill. They also live exceptionally long for their body size, resisting cancer and the ravages of ageing. A 2025 companion study using Bat1K data showed that immune gene adaptations for viral tolerance and disease resistance emerged at the very base of the bat lineage. “What we have now is a kind-of code book of life,” Olson said.
Ariadna Morales, an evolutionary biologist who worked on both papers, puts the medical potential bluntly. The genetic mechanisms bats use to suppress inflammation, repair DNA, and tolerate viruses could inform therapeutics for zoonotic diseases, cancer, and human ageing. Researchers are already probing why certain Myotis species succumb to white-nose syndrome — the fungal pathogen that has killed millions of hibernating bats in North America — while others do not. The genome map may hold the answer.
Conservation Crisis Looms
Half of all bat species have unknown or declining populations. Eighteen percent are threatened with extinction, according to the IUCN. Climate change, habitat loss, persecution, and harvesting for bushmeat are driving declines. Liliana Dávalos, a conservation biologist at Stony Brook University and study co-author, warns that bats’ reproductive biology — typically one or two pups per year — makes recovery agonisingly slow. “When individuals drop dead from scorching temperatures, or get killed through persecution, populations cannot quickly recover their numbers,” she said.
Yet bats are ecological linchpins. They pollinate crops, disperse seeds, and consume vast quantities of insects — including mosquitoes that spread human disease. Losing them would cascade through ecosystems and economies alike.
Why it Matters
This study does more than settle an academic debate about where bats began; it hands medicine a 65-million-year-old blueprint for surviving viruses, evading cancer, and defying ageing — traits forged in the crucible of flight and high metabolism. At the same time, it illuminates which lineages are most vulnerable to the fungal and climatic threats already decimating populations. Understanding the bat genome is no longer just evolutionary curiosity. It is a prerequisite for pandemic preparedness, novel drug discovery, and the conservation of the mammals that keep our ecosystems in balance.