This finding could mean that scientists have been underestimating how global climate change will affect biodiversity and the number of extinctions that will occur, according to a study published in the journal Proceedings of the National Academy of Sciences.
The authors of the study from the University of British Columbia (UBC) in Canada and the University of Montpellier in France explained that for species to survive climate change, they will have to genetically adapt or shift their ranges—or both.
When the environment that a species lives in changes rapidly, naturally occurring genetic mutations that are beneficial to the new conditions may be favored by natural selection. Over time, these mutations spread among a population, conferring new abilities on the animals that enable them to adapt.
Meanwhile, species can also disperse across landscapes under a changing climate to live in environments that contain more favorable conditions.
As species adapt and disperse due to new conditions, we might expect these two factors in combination to increase the chances that they will survive, according to the researchers. However, we currently have a limited understanding how these two separate processes interact.
In fact, the latest study suggests that dispersal and adaptation may not necessarily lead to increased species persistence as may be expected.
“Climate change is a major threat to biodiversity, but most of our understanding of how species persist when the environment changes does not take into account interactions between species,” Patrick Thompson, an author of the study from UBC, told Newsweek. “My colleague, Emanuel Fronhofer, and I wanted to fill this gap by asking how entire assemblages of species would respond to environmental change.”
For the research, the scientists used a computer simulation model to see how multiple species might respond to climate change as a whole. Previously, studies that have looked at the issue of adaptation and dispersal have tended to look only at single species, the authors noted.
This model found that both dispersal and adaptation on their own increased biodiversity over time. However, when species both disperse and evolve, the “faster adapting species persist in their current ranges, preventing others from shifting their ranges to track environmental change,” the authors wrote in the study.
This could lead to the extinction of the slower-adapting species, according to Patrick Thompson, one of the authors of the study from the University of British Columbia.
“If we don’t account for both dispersal and adaptation, we can overestimate how many species might survive in a changed environment,” Thompson said in a statement. “The good news is this conflict between moving and adapting is reduced when movement rates are high, which emphasizes the importance of maintaining well-connected landscapes.”
Thompson said the latest research highlights the damage that the fragmentation of habitats—through the construction of infrastructure, for example—can cause. He said it is essential that wildlife corridors—through which animals can move freely—are preserved.
Scientists believe that the Earth is currently going through the sixth mass extinction event in its history, with species disappearing significantly faster than historical baseline rates.
In fact, a landmark U.N. report recently warned that 1 million species around the world are at risk of disappearing due to human pressures and climate change.
