The bank vole, a tiny, chestnut colored rodent with a hairy tail and stout nose, spends most of its time eating berries, seeds, and grasses and scuttling through the underbrush of wooded areas or hedges. Overall, this small rodent is rather unassuming. You may even mistake it for a mouse if you come across one, and shortly after, pay it no mind.
What you may not realize, however, is that beneath the soft fur of this petite rodent lies an evolutionary secret. The bank vole's ancient DNA contributes to a major mystery of today: “How will animals adapt to climate change and survive in a warming world?”
In locations where the climate continues to warm, some animals will develop larger limbs and ears to increase surface area and facilitate greater heat loss, according to the Natural History Museum. Other animals, such as parrots, may develop larger bills or beaks to help regulate body temperature. Instead of growing larger appendages, some animals may see an overall decline in body size.
But for the bank vole, it’s not about large ears, smaller bodies, or habitat loss. These small rodents’ climate-change adaptability has more to do with their ancient ancestors than the new climate. Thanks to ancient populations of bank voles that had been isolated in different glacial regions and came back in contact during the Last Ice Age, they may have exchanged genetic variants that future generations can draw on as they adapt to the changes in their present-day climate.
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Bank vole, as part of the Communications Biology research.
(Image Courtesy of Petr Kotlik)
What the findings of a recent study published in Communications Biology seem to confirm to Hayley Lanier, the associate curator at the Sam Noble Museum, part of the Oklahoma Museum of Natural History and one of the study’s authors, is that for a mammal population that’s adapting to the future, the key to success is holding on to gene variants. And as a researcher, understanding those variants and adaptations could help benefit animal conservation in the future.
“The variants that we're finding that are important for climate change adaptation […] are these widespread variable genes […], a really important toolkit for responding to change in the species,” Lanier, who is also an associate professor in the School of Biological Sciences at the University of Oklahoma, told Discover.
These findings also expand far beyond that of a single rodent species. Climate change is already shifting ecosystems across the globe much faster than some animal species have experienced in their more recent evolutionary histories. Species are feeling the pressure to adapt as their homes and food sources change. And in the future, genetic diversity and past variation may be more important than mutations.
Evolution Is No Longer a Historical Process
It’s easy to think of evolution as something of the past when we look back at fossil records and genealogical evidence left behind by life on Earth before the modern age. But, even as we sit here, going through our day-to-day tasks, life is still evolving.
Bacteria can rapidly adapt to certain antibiotics and become antibiotic-resistant. Some urban lizard populations have evolved stickier toes to climb windows more easily, and some urban raccoons may be developing shorter snouts as they adapt to eating human food and living in more urban environments.
Evolution is happening before our eyes, and in some cases, humans are a major driver of it. Human-caused climate change is already shifting so many of Earth’s normal patterns, from weather patterns to migration times to snow and rainfall. These shifts are having a major impact on organisms around the globe.
“For a lot of animals, some of the bigger effects are going to [happen] in two categories. One of them is going to be sort of resource availability and timing,” Lanier said. By timing, Lanier refers to breeding and migration. A changing climate could alter the timing of these vital processes, i.e., babies being born earlier or migrations starting later. When animals migrate or reproduce, they need to have certain resources, like food and shelter, available. If the timing is off, some of those resources may not be available.
This could lead to fewer offspring being born and population decline.
“The other thing that we see […] are these sort of unpredictable weather swings,” Lanier added.
Severe droughts lead to fewer water sources for people and animals and a reduced ecosystem capable of sustaining aquatic life. Less water also impacts food sources. Heavy rainfall is also leading to massive landslides and habitat destruction for vulnerable species. Higher temperatures are putting strain on some animals as well.
For some species, including the American Pika, which Lanier spent much of her early career studying, struggle with rising temperatures. Pikas, small rodents that look like a cross between a rabbit and a mouse, live in the alpine zone and prefer cooler temperatures, as they typically can’t survive in temperatures over 75 degrees Fahrenheit without cooler refuges.
It was during her time studying pikas that Lanier discovered that collared pikas, which live in Alaska and Canada, have lower genetic diversity than American pikas, likely due to a genetic bottleneck. American pikas had a much deeper genetic lineage. These findings led Lanier to the question, How can a species' past population history shape its ability to adapt to a changing future?
This question led Lanier to the bank vole.
Read More: Climate Change May Be Making Our Days A Little Longer — Here's How We Know
How The Bank Vole Changed What We Know About Climate Adaptations
In the 2026 study, the team researched bank vole populations in Britain and other parts of Europe. They found that in British populations, bank voles had widespread genetic variation, a crucial factor that facilitates adaptation.
Bank vole, as part of the Communications Biology research.
(Image Courtesy of Petr Kotlik)
“Bank voles are a really good case of a highly adaptable mammal,” Lanier said.
Bank voles make for an excellent study subject, as they can be found across all sorts of terrain and ecosystems in Europe, according to Lanier.
Lanier and team sampled genome data from 151 bank voles (Clethrionomys glareolus) from Britain and four other regions in mainland Europe. These populations represent two groups: the Western refugia and the Carpathian refugium — two populations that live in different climates.
The team analyzed the voles’ genomes to determine their alleles — variants or alternative forms of a gene. What they predicted was that, while analyzing the voles’ genomes, the warmer-climate lineages (voles from warmer regions) would most likely carry more warm-adapted alleles, or gene variants that make them more adaptable to warmer regions. On the other hand, they predicted that colder-climate lineages would carry more cold-adapted alleles — variants that help them better adapt to colder regions.
What they found challenged their expectations.
“The variants that we're finding that are important for climate adaptation are ones that, at least sort of disproportionately, are these widespread variable genes,” Lanier said.
Widespread variable genes — genes that show higher signs of diversity or fluctuating expression across different individuals or environmental conditions, according to the National Library of Medicine — were found in voles from across the continent, and not just from a distinct lineage. Variable genes allow a species to have a more diverse ‘toolkit’ which can help them adapt to stress, such as a changing environment.
In the case of the bank vole, the populations without this diverse toolkit, usually local, one-off genetic populations, are less likely to adapt well to climate stress, as they don’t have the genetic makeup that makes adaptation easier, Lanier said. The voles with the toolkit, however, have what it takes to better adapt to these stresses.
From this study, it may be possible to create a template to examine other species' genetic histories and toolkits that help a species adapt to climate change. And in contrast, reveal which species do not have the toolkits necessary for adaptation.
How Will Animals Change in the Future?
What the bank vole study and other research seem to highlight about how animals will appear as they adapt to climate change has less to do with major shifts in appearance and more with subtle changes.
“At least some animals are getting smaller in response to climate change,” John Wiens, a professor of ecology and evolutionary biology at the University of Arizona, told Discover.
A 2025 study in Science Advances revealed that some clownfish species may shrink to better withstand heat stress, while a 2022 study published in Nature Ecology and Evolution suggested that some bird species across North America may be declining in body size to keep cool.
Wiens has also noticed that besides evolutionary changes and adaptations to climate change — changes that are passed down genetically — science is also seeing “plastic changes.”
These physical trait and behavior changes can occur within an individual’s lifetime as a response to environmental changes, but do not change the genetic code, according to Nature. Wiens gave examples of frogs breeding earlier in the year, as spring may “arrive” sooner now.
Unfortunately, not every animal has the genetic toolkit needed to quickly adapt to a changing climate. And many could go extinct.
“It seems quite possible that we'll lose like a third to half of all animal species on the planet; that's definitely not impossible in the next 50 to 100 years when climate change reaches its peak,” Wiens said.
Animals that will likely not survive as well, according to Wiens, are those with small ranges or those confined to smaller regions, such as black-and-white ruffed lemurs, which are found only in Madagascar.
Wiens also points out that there are still animals we have not discovered yet.
“The majority of animal species are undescribed, almost certainly undescribed insect species, and a lot of them have small ranges and will probably be really sensitive to climate change because of that,” Wiens said.
How We Can Help Future Species
If this should come to pass, Wiens thinks future ecosystems will likely feel less diverse and animals with wider ranges will be more prevalent. We’ve already seen some animals adapt better to urban environments as habitats shift. Animals like coyotes, rats, and pigeons cover wide territorial ranges around the world and have adapted well to urban life.
Animals with smaller regions and less adaptable traits, physical or genetic, will likely be the first to go extinct. Even animals that can adapt better may go locally extinct as certain regions become uninhabitable.
While the impacts of climate change are already taking root, there are still ways we can mitigate some of the effects and work to help animals survive in the future. As Wiens said, we’re all in the same boat here, and we have the ability to steer that boat in a new direction.
Lanier shares a similar sentiment. There is still a lot of work to be done, but we can make steps towards conservation and protection that can help species survive. Bank voles already seem to be in a better position than some other animals. By preserving species' genetic variety and keeping populations strong and healthy, we can help ensure that more animals could survive a shifting climate.
“I think before we get you know too excited about sort of ‘science-ing’ our way out of this, we should try to say, what are just small things that we could do right now in terms of preservation and protection that would have a big impact, and I think there's a lot of people working in that space with really good ideas,” Lanier said.
Read More: Severe Drought Exposes Historic Shipwrecks Along the Danube River
Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
- This article references information from the Natural History Museum: Animals 'shapeshifting' to adapt to rising temperatures
- This article references information from a study published in Communications Biology: Origins of adaptive genomic variation in a wild rodent
- This article references information from Healthline: Understanding the Relationship Between Antibiotics and Bacteria
- This article references information from the BBC: Extreme evolution: The animals evolving at super speed to survive
- This article references information from the National Library of Medicine: Widespread inter-individual gene expression variability in Arabidopsis thaliana
- This article references information from a study published in Science Advances: Individual clown anemonefish shrink to survive heat stress and social conflict
- This article references information from a study published in Nature Ecology and Evolution: Abiotic conditions shape spatial and temporal morphological variation in North American birds
- This article references information from a study published in Nature: Phenotypic Plasticity and Adaptive Evolution
