One of the most enduring mysteries in mammalian evolution has finally been cracked. For decades, scientists have argued about where bats — the only mammals capable of true powered flight — first appeared on Earth, with rival hypotheses pointing to Africa, Asia and North America. Now, a landmark study led by researchers at University College Dublin and published in the journal Nature has rewritten the bat family tree, presenting strong evidence that the winged mammals most likely originated in Europe during the late Palaeocene epoch, roughly 65 to 60 million years ago, in the evolutionary aftermath of the extinction that wiped out the dinosaurs.
The scale of the undertaking is unprecedented. The research represents the largest combined bat genome and fossil study ever attempted, drawing on samples collected over decades from bats around the world, including some of the rarest and most unusual species found only in the most remote locations. An international team of 137 researchers from 64 countries, working as part of the Bat1K consortium — a global initiative dedicated to sequencing the genomes of all living bat species, co-founded by UCD’s Professor Emma Teeling — combined genomic data from every living bat family with the ancient fossil record to reconstruct the evolutionary history of this extraordinary lineage.
The technical achievement behind the study is considerable. The team analysed 103 bat genomes, including 42 newly generated chromosome-level assemblies, representing all 21 recognised bat families. These genomic data were then integrated with evidence from 44 fossil bats, using computational approaches capable of modelling the evolution of living and extinct species together. By placing fossils within a genomic framework rather than treating them as separate lines of evidence, the researchers were able to identify the oldest branch of the bat family tree while accounting for the molecular data, and to pinpoint when and where bats first emerged.
The results paint a strikingly clear picture. Bats most likely first evolved in Europe during the late Palaeocene, and from there their descendants spread into Africa. As the animals diversified, different groups then expanded independently into the Americas, Asia and Australia, eventually giving rise to the major bat lineages found across the planet today. Alongside establishing this likely geographic cradle, the study resolves several long-running debates about the relationships between bat families, revealing unexpected connections between some of the world’s most unusual bats and overturning conflicting evolutionary trees that had persisted for decades.
Among the study’s most significant findings is new light on how bats developed the two defining characteristics that set them apart: powered flight and echolocation. Because bats are the only mammals known to have evolved true powered flight, the findings point to Europe as the most likely place where mammalian flight first took to the air. Meanwhile, analysis of the fossil bat Vielasia, which sits on the oldest branch of the bat family tree, indicates that echolocation had already evolved near the very beginning of bat evolution. Together, these results suggest that both powered flight and echolocation predate the diversification of modern bats — a combination that may help explain the group’s extraordinary evolutionary success.
Reaching that conclusion was far from straightforward. Different parts of the bat genome can tell different stories about their evolutionary history, because early bat lineages appear to have exchanged genes as they diversified. This means that while some genomic regions suggest one set of relationships among bat families, others point to another, muddying the signal that phylogeneticists rely upon. The breakthrough came when the researchers discovered that a region of the X chromosome retained a particularly clear signal of the underlying relationships between bat groups, allowing them to cut through the conflicting evidence and resolve the family tree with new confidence.
The team also computationally reconstructed the genome of the ancient ancestor from which all living bats descended, offering a glimpse into the genetic make-up of one of the earliest flying mammals. This ancestral genomic resource now gives scientists a powerful new tool for investigating the genetic changes behind bats’ remarkable diversity and adaptations, including flight, echolocation, exceptional longevity and resistance to disease. Because many bat species show remarkable resistance to pathogens and live far longer than their body size would predict, the resource could eventually inform human research into ageing, immunity and disease resistance.
The significance of the work is not lost on the scientists behind it. “It is extraordinary, after decades of research and conflicting findings, we finally have a robust phylogenetic tree that we can now use to properly understand how and where bats’ unique traits evolved,” said senior author and co-founding Director of Bat1K Professor Emma Teeling of the UCD School of Biology and Environmental Science. “We also have the genomes to uncover the molecular basis of these spectacular mammalian adaptations and know where the fossil bats fall in this tree.” Contributing to the project from UCD were Assistant Professors Graham Hughes and Zixia Huang, both of the School of Biology and Environmental Science.
Other senior authors emphasised the methodological and collaborative milestones. “The approach we used to model the evolution of fossil and living species together can do what other methods cannot — identify the oldest group of fossil bats while taking the genomic data into account, and uncover when and where bats originated,” said Professor Liliana M. Dávalos of Stony Brook University. “We combined state-of-the-art DNA sequencing and computational methods to generate and compare these genomes and identify the genes they contain,” added Professor Michael Hiller of the Senckenberg Research Institute in Frankfurt. Professor David Ray of Texas Tech University noted that the dataset allows scientists to investigate genomic variation ranging from single base changes to hundreds or thousands of bases missing from one lineage but present in another — variation that has given rise to the huge diversity of bats sharing the planet, and to the origins of their unique characteristics.
“Bats constantly surprise us. They are one of evolution’s greatest experiments,” said senior author Professor Sonja Vernes of the University of St Andrews, and Bat1K co-founding Director. “This extraordinary genomic resource, the culmination of years of international cooperation of Bat1K, is finally allowing us to understand how their remarkable biology evolved.” The achievement rests on decades of fieldwork: “This dataset represents decades of work by field researchers from around the world, collecting samples from some of the most remote places, from New Zealand to Madagascar,” said Professor Teeling. “None of this would have been possible without the dedication and collaboration of these researchers, working together through the Bat1K consortium to bring these samples together, allowing us to tell the evolutionary history of these extraordinary flying mammals.” The study was supported in part by the European Research Council, Science Foundation Ireland and the Irish Research Council, alongside international partners.
Bats are among the most extraordinary mammals on Earth. They account for one fifth of all living mammal species, playing a vital role in maintaining healthy ecosystems across the globe as pollinators, seed dispersers and controllers of insect populations. Most bats orient and hunt in complete darkness using sound alone, a sensory feat few other animals can match. Yet despite their unique biology and ecological importance, scientists have struggled for decades to answer some of the most fundamental questions about their evolution. With a robust phylogenetic tree now in hand, anchored by the fossil record and built from genomes spanning every living bat family, researchers finally have the framework they need to trace how — and where — one of evolution’s most remarkable experiments first took flight.
Subject of Research: Evolutionary origins and phylogeny of bats based on combined genomic and fossil analysis
Article Title: Bats originated and took first flight in Europe, new UCD-led research suggests
Article References: Bats originated and took first flight in Europe, new UCD-led research suggests. (n.d.). Original publication
Image Credits: AI Generated
DOI: Not provided
Keywords: bats, evolution, genomics, phylogenetics, fossils, Palaeocene, echolocation, powered flight, Bat1K, Nature, Europe, University College Dublin
News Source: Juliet Wilcox. (October 18, 2026). Bats Took Their First Flight in Europe, Landmark Genome and Fossil Study Finds. Scienmag.
