Bat1K Consortium: 137 Researchers from 64 Countries Trace Bat Origins to Europe in Nature Cover Study

Overview

More than 1,500 bat species make up one fifth of all living mammals. They are the only mammals capable of true powered flight, most hunt in total darkness using echolocation, live disproportionately long for their size, and resist viruses that are lethal to other mammals. Where bats came from has been debated for sixty years. On 23 September 2026, the cover of *Nature* offered an answer: Europe.

• Paper: *Reference Genomes and Fossils Revise Bat Family Phylogeny and Biogeography*, Nature, 2026-09-23
• DOI: 10.1038/s41586-026-11007-3, open access
• Team: Bat1K consortium, 137 researchers from 64 countries; co-founding directors Emma Teeling (UCD and Wellcome Sanger) and Sonja Vernes (St Andrews); Yan Liang (Sanger) as first author; Nicole Foley and William Murphy (Texas A&M) contributed recombination-aware phylogenetic methods

Where the Data Came From

• 103 high-quality genomes covering all 21 currently recognized bat families, including 42 newly generated chromosome-level assemblies
• 44 fossil specimens from around the world, combined with morphological data from living individuals to form the largest dataset of extinct and extant bat morphology to date
• Samples collected across decades, including some of the hardest-to-obtain taxa: the bumblebee bat of Thailand and Myanmar (widely considered the world's smallest mammal), Madagascar's sucker-footed bat (with adhesive discs on wrists and ankles for clinging to smooth leaves), and New Zealand's lesser short-tailed bat (which walks on folded wings used as forelimbs)

Three Conclusions

First, bats originated in Europe. The timing is placed in the late Paleocene; secondary sources differ slightly (approximately 65 million years ago, or 65–56 million years ago, or over 56 million years ago). This revision overturns earlier hypotheses of Asian, African, or North American origins. The earliest bat lineages later spread to Africa, forming a Europe–Africa hub, and from there dispersed to Asia, the Americas, and Australia.

Second, echolocation predates the diversification of modern bats. The fossil bat *Vielasia* sits on the oldest branch of the family tree, meaning laryngeal echolocation already existed before modern bats began to diverge. This supports the reading that both signature traits — flight and echolocation — were established near the origin of the bat lineage, contrary to the hypothesis that echolocation evolved independently in multiple lineages.

Third, several family-level relationships were reshuffled. Madagascar's sucker-footed bat was placed as the earliest branch of a large group that also includes evening bats and free-tailed bats. These relationships had previously been studied with few species, fragmented assemblies, or small genomic windows, producing conflicting results. The new framework employs recombination deserts on the X chromosome (XLRD) to resolve conflicting signals within genomes. This region has been conserved in mammals for over 100 million years, and Foley and Murphy's earlier *Nature* paper showed it can preserve deep evolutionary history obscured by hybridization.

The team also reconstructed the ancestral genome of all living bats — the genome of the first flying mammal.

Why Build These 103 Genomes

First author Yan Liang emphasizes the "dark genome" — previously little-explored regions that may carry strong evolutionary signals. With an evolutionary map in place, researchers can now search systematically for genes behind traits like longevity and disease resistance: at which loci, through which pathways, and conserved across which families. The authors note this resource may connect to human research on aging, immunity, and disease resistance — a proposed direction, not a validated conclusion.

Caveats

• This is a reconstruction of evolutionary history, constrained by the incompleteness of the fossil record and the precision of time calibration. The paper's wording is "most likely originated in Europe," and it does not claim to have excluded all alternatives.
• The timing of echolocation hinges on the placement of a single fossil genus (*Vielasia*); if that placement is revised, the conclusion must be re-evaluated.
• Only the 21 extant families plus some fossils are covered; the African fossil record is inherently sparse, and while the African-origin hypothesis was rejected by this combined evidence, it was not independently tested under equally strong evidence.

Why It Matters

Hypotheses about bat origins rotated repeatedly between 1915 and 2019, each rewritten as fossil or genomic evidence updated. Moving echolocation from "independently evolved across families" to "present at the origin" collapses a multiple-origin hypothesis into a single origin — an unusually clean result in taxonomy. Ancestral genome reconstruction gives the question of how flight evolved its first comparable baseline, and research into bat antiviral capacity now moves from scattered single-family samples to all-family comparisons — a shift in tools that arrived even before the conclusions.