Level 1 — Absolute Beginner

Bats are the only mammals that can truly fly. Where did they come from?

A new study says the first bats lived in Europe. This was about 65 million years ago.

Later, bats moved to Africa, Asia, the Americas and Australia. Today there are bats almost everywhere.

bat

A small animal that flies at night.

mammal

An animal that feeds its babies milk.

fly

To move through the air.

Europe

A continent that includes Spain and Germany.

million

A thousand thousands.

study

Careful research to learn something.

fossil

A very old animal or plant kept in stone.

move

To go from one place to another.

Level 2 — Elementary

Where did bats begin? A big new study in the journal Nature says the answer is Europe. The researchers think bats and mammal flight began there about 65 million years ago.

The team came from 64 countries and had 137 scientists. They compared 103 bat genomes, including 42 new ones, and added evidence from 44 fossil bats.

The study says the first bats moved from Europe into Africa. From there they spread to Asia, the Americas and Australia.

The scientists also found that true flight and the sound-based sense called echolocation appeared early, about 50 million years ago. Older ideas had put the start of bats in Asia, Africa or North America.

journal

A magazine for scientific research.

genome

All the genetic information of a living thing.

evidence

Facts that show something is true.

echolocation

Finding objects by listening to echoes of sounds.

appear

To begin to exist.

spread

To move over a wider area.

team

A group that works together.

compare

To look at things to see how they are alike or different.

Level 3 — Intermediate

Bats are the second largest group of mammals, yet their origin has long been murky. A landmark study in Nature now proposes that bats, and with them mammalian flight, arose in Europe around 65 million years ago, overturning earlier hypotheses that pointed to Asia, Africa or North America roughly 50 million years ago.

The Bat1K consortium, a team of 137 researchers from 64 countries, reconstructed the family tree by analysing 103 bat genomes. Forty-two of them were newly assembled at chromosome level and together represent all 21 recognised bat families. The genetic evidence was combined with data from 44 fossil bats to calibrate the timeline.

According to the analysis, early bats spread from Europe into Africa, creating a hub between the two continents. From there they expanded into Asia, the Americas and Australia as the climate and landscapes changed.

The researchers also concluded that true flight and echolocation evolved early, about 50 million years ago, rather than arising separately several times after modern bat lineages began to split apart.

murky

Unclear or poorly understood.

hypothesis

A proposed explanation that can be tested.

consortium

A group of organisations working together.

genome

A complete set of an organism's genes.

calibrate

To adjust or fix a measurement against known points.

hub

A central point from which things spread.

lineage

A line of descent from a common ancestor.

overturn

To reverse an earlier belief.

Level 4 — Advanced

For a group that makes up roughly a fifth of all mammal species, bats have kept their origins remarkably obscure. A landmark paper in Nature now offers a bold answer: the first bats, and with them powered flight in mammals, arose in Europe about 65 million years ago, a finding that upends hypotheses favouring Asia, Africa or North America around 50 million years ago.

The conclusion rests on a formidable dataset assembled by the Bat1K consortium, a collaboration of 137 researchers from 64 countries. They analysed 103 bat genomes, 42 of them newly generated at chromosome level and covering all 21 recognised families, and anchored the molecular clock with evidence from 44 fossil bats.

The reconstruction portrays Europe and Africa as a joint evolutionary hub. From that crossroads, bats radiated into Asia, the Americas and Australia, adapting to a patchwork of habitats and diets that now ranges from insect hunters to fruit specialists.

The authors further argue that true flight and echolocation emerged once, early, around 50 million years ago, rather than being repeatedly reinvented by separate lineages, a parsimonious reading that reshapes how biologists think about one of evolution's most distinctive sensory and locomotor innovations.

obscure

Not clearly known or understood.

upend

To overturn or turn upside down.

formidable

Impressively large or powerful.

anchor

To fix firmly in place.

molecular clock

A method that estimates timing from genetic change.

radiate

To spread outward from a central point into many forms.

parsimonious

Favouring the simplest adequate explanation.

locomotor

Relating to movement from place to place.