Researchers from the Autonomous University of Barcelona have made a remarkable discovery about how fruit flies are rapidly adapting to the effects of climate change. By studying the genetic variations in Drosophila subobscura populations across Europe, they have uncovered an unexpected evolutionary response that could have significant implications for understanding the impact of global warming on other species.
Genetic Adaptations to Heat
Their research shows that since the late 1990s, as the warming trend and the intensity of heat waves have grown more severe, fruit fly populations have evolved with an equally noticeable escalation in number of genetic mutations that provide greater resistance to extreme temperatures.
This evolutionary response is particularly interesting because it does not require the invention of new genetic variations, but rather a change in the frequencies of those that already exist. So some of chromosomal inversions help individuals to be more heat tolerant, but others – to survive cold. His team saw a stark transition — the heat-tolerant inversions were increasing in frequency at the cold range edge of the fly, while away from it and towards the center of a more historically warm distribution, there was declining frequency for cold-adapted inversions.
Consequences for Other Species
As a result of this the research tentatively implies that global warming is happening too fast for many species to cope by evolving. A typical model organism was investigated: Drosophila subobscura, a good example of investigation uncovering the importance of genetic diversity in allowing temperature adaptation across latitudes.
But the researchers caution that this may not be sufficient for other insect species—without distance in the genome, similar levels of variability would suggest worse news. Should the rapid warming trend continue as it is, few species will be able to outrun extinction.
Conclusion
The results of the study are a mix of optimism and pessimism. While representing a remarkable ability to cope with climate change for at least some species, the 150 generations of evolution in fruit flies illustrates that adjustments can occur relatively rapidly to anticipate milder temperatures. Nonetheless, the researchers warn that these traits may not apply to much of life — especially when a species boasts low levels of genetic diversity. We hope these results fill a gap of knowledge, as we expect that understanding and tracking the evolutionary responses of different species will be important to designing effective conservation management strategies and minimising the consequences of rapid global warming.
