Fruit Flies Likely to Fall Victim to Climate Change
Many species are being forced to adapt to slowly rising temperatures around the world. However, some simply do not have the ability to change. They are stuck in a sort of "evolutionary straitjacket." This includes many species of fruit fly, a common bug found in many houses circling overripe or rotting fruit. According to new research from Monash University, these species may face extinction in the near future, given current projects of a 3 degree C increase in mean annual temperature in the next century and even greater temperature extremes.
Fruit flies are small, ranging in color from yellow to black. They are found all around the world in all kinds of ecosystems, but more species are found in tropical regions. Fruit flies are found in the genus, Drosophila, a Latin adaptation of the Greek word meaning "dew-loving".
According to the phylogeny (evolutionary tree) of drosophila, high heat resistance is a feature only found on some of the branches. The other evolutionary branches have very limited ability to change their level of heat resistance. This is true even if a fly which is native to a cooler environment spends its entire life in a warmer environment. Even this fly's heat tolerance is not significantly altered.
"Given our findings, these expected increases pose a major threat to biodiversity in the near future. Particularly as Drosophila or fruit fly findings are often more broadly applicable," said Dr Kellermann of the Monash University School of Biological Sciences.
Kellermann and fellow researchers looked at nearly 100 fruit fly species and found that they had evolved to temperature and humidity extremes within their specific environment. At the same time, that evolution allowed for very little flexibility to change their levels of heat resistance, making them vulnerable to changes in climate.
"If a species can only withstand temperatures of 36ºC and the maximum temperature of the environment is already 36ºC, an increase of even 1ºC would already put this species over the edge towards extinction," Dr Kellermann said.
Species found in the tropics and mid-latitudes are most likely to fall within the category of most at-risk.
This study has been published in the Proceedings of the National Academy of Sciences.
Fruit Fly image via Shutterstock