A major study of bat genetics and fossils is changing the scientific picture of how the world's only mammals capable of true powered flight evolved.
Published in the journal Nature on September 23, the research combines chromosome-level genome data from 103 bat species with evidence from 44 fossil bats. The dataset represents all 21 currently recognised bat families and was assembled by an international team of 137 researchers from 64 countries.
Editorial Insight
Key Highlights
Important points readers should notice.
Issue/Event: New research revises the evolutionary history of bats.
Location: Europe identified as the most likely origin of the bat lineage.
Authority/Organisation: International Bat1K research consortium; study published in Nature.
Action Taken: Researchers combined 103 genomes with fossil and morphological evidence.
Impact: The findings provide a new framework for understanding the origin, diversification, flight and echolocation of bats.
The researchers conclude that bats and mammalian powered flight probably originated in Europe during the Late Palaeocene, around 65 million years ago.
That conclusion differs from earlier hypotheses that had placed the origin of bats in Africa, Asia or North America.
How scientists reconstructed the bat family tree
Editorial Analysis
Why This Matters
The research is significant beyond simply identifying where bats originated. Bats possess biological traits that are unusual among mammals, including powered flight, echolocation, long lifespans in some species and notable resistance to several diseases. The new genomic resource gives scientists a stronger evolutionary framework for studying how these characteristics developed. It could also help future research examine the genetic basis of traits such as disease resistance and longevity by comparing bat genomes across species and evolutionary branches.
The study did not rely on fossils alone.
Researchers compared large-scale genetic information from living bats with anatomical characteristics preserved in fossils. The analysis included 103 genome assemblies, including 42 generated for the study, and a morphological dataset covering 699 characteristics from 65 species. The fossil component included 44 pre-Quaternary specimens.
Combining these different forms of evidence allowed the researchers to build a more detailed evolutionary tree.
This matters because genetic comparisons between living species can produce different evolutionary histories depending on which parts of the genome are examined. Fossils provide an additional time and anatomical reference that can help place those genetic relationships into an evolutionary timeline.
Europe appears to have been the starting point
The combined analysis points to Europe as the most likely starting region for the bat lineage.
The researchers estimate that the earliest bat lineage emerged roughly 65 million years ago before its descendants spread into other parts of the world.
The study indicates an early movement from Europe toward Africa, followed by wider expansion into Asia, the Americas and Australia.
The finding does not mean every early bat species lived only in modern-day Europe. Rather, the genomic and fossil evidence supports Europe as the most likely geographical origin of the lineage from which later bat diversity developed.
Flight may be as old as bats themselves
One of the study's important evolutionary findings concerns powered flight.
Bats are unique among living mammals because they can generate true powered flight. Exactly when this ability emerged has been difficult to establish because the earliest stages of bat evolution are poorly represented in the fossil record.
The new analysis indicates that mammalian powered flight probably appeared near the beginning of bat evolution, around the same broad period as the emergence of the lineage itself.
This provides a different picture from the idea that bats first evolved as ground-dwelling or climbing mammals and only much later developed fully powered flight.
Echolocation also appears to be ancient
The study also provides evidence about echolocation, the sound-based navigation system used by many bats.
Researchers placed the fossil genus Vielasia within the oldest branch of the bat family tree. Its position suggests that laryngeal echolocation existed before the diversification of modern bats.
In other words, two of the features most strongly associated with bats — powered flight and echolocation — may have appeared very early in their evolutionary history.
That helps explain how bats were able to occupy a wide range of ecological niches over millions of years.
