30 SEP 2026 — The largest study yet of bat genomes and fossils, published in Nature on 23 September, concludes that bats, and with them powered flight in mammals, most likely began in Europe. It rejects earlier proposals that bats arose in Africa, Asia or North America.
The analysis also redraws parts of the bat family tree and suggests echolocation, the ability to navigate by sound, was present near the very start of bat evolution.
The dataset
The Bat1K consortium assembled high-quality, chromosome-level genomes from 103 bat species, 42 of them new, covering all 21 living bat families. The paper combines them with a dataset of 699 anatomical characters for 65 species, including 44 fossil bats.
Analysing living and extinct species together lets the fossils anchor both the dates and the geography of the tree. Earlier attempts leaned more on living species or on fragmentary genomes, and reached conflicting answers.
Europe first, then Africa, then everywhere
The model places the common ancestor of bats in Europe in the late Palaeocene, with a posterior probability of 99.2%. From there, descendants most likely spread to Africa. From that Europe–Africa base, different groups later expanded independently into the Americas, Asia and Australia as modern bats diversified in the early Eocene.
The paper notes that the oldest known bat fossils, about 56 million to 52 million years old, come from Asia, North America, Europe and Australia. By then bats could already fly and echolocate, so the fossils alone could not show where bats began. Some coverage, including Euronews, dates the origin to 65 million years ago; the paper's own summary says only the late Palaeocene.
"Our findings point to Europe as the most likely place where mammalian powered flight first evolved," Emma Teeling of University College Dublin, a senior author, said in the university's release.
Echolocation may predate modern bat groups
The study places the fossil bat Vielasia, which could echolocate, in the oldest branch of the bat tree. If that placement is right, echolocation predates the split into modern bat groups.
The support for that placement is weaker than for the European origin. The paper gives it a posterior probability of 68%, a level it describes as medium.
Why the tree was hard to draw
Different parts of bat genomes tell different stories about how the families are related, probably because early lineages exchanged genes. The release says a region of the X chromosome kept a clearer signal, which helped settle long-running disputes. The paper also resolves where the Madagascan sucker-footed bats, family Myzopodidae, belong: as the earliest branch of the superfamily Vespertilionoidea.
What the genomes are for
The genomes are the part other researchers will keep using. Bats resist many viruses, live unusually long for their size and hibernate, and the researchers say the resource can be used to study the genetics behind those traits.
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