Researchers have discovered that dragonfly species with darker wings have evolved to better withstand heat and attract mates. This finding sheds light on the complex relationship between thermal tolerance and sexual signals, and how it may influence the survival of species in a warming climate. Dragonflies are a fascinating group of insects that have captivated the attention of biologists for their unique adaptations.
The Dark Wing Coloration Evolutionary Tradeoff
While biologists have devoted significant effort to understanding the impact of heat tolerance on species survival, little is known about how thermal traits affect reproduction-a factor that is directly related to extinction risk. University of Pittsburgh researchers studied dark wing coloration in dragonflies to see how it relates to heat tolerance.
Comparing dragonfly species, the study showed those with dark wing coloration — which absorbs heat — have evolved to better withstand higher temperatures. This may be an important evolutionary adjustment since the dark wing ornaments might increase body temperature by up to 1-2°C and become physiologically stressful, or even cause males to abandon their reproductive territories.
Sexual signals and Thermal Tolerance: A Connection.
Sexual signals function as cues in mate choice and reproduction across animals, including dragonflies. The dark wing colouration of dragonflies helps them in succesful mate finding, to distinguish between and only mate with the correct species, and setting up mating contests correctly. This adaptation does come with a downside as the greater heat absorption can endanger the very existence of dragonflies.
Download Image It appears that the observed co-evolution between heat tolerance and wing coloration was even more pronounced among tropical species as opposed to those occurring in regions with lower average temperaturesisible wavelengths, according to the researchers. This fits with the idea that dragonflies need to be adapted to high temperatures to prosper in their habitats and do well reproductively.
Significance of Species Responses to Climate Change
Its results have major implications for how we expect various species to respond in the face of climate change. PeerJ Previous findings suggest that selective pressure from rising temperatures may push some brightly-colored dragonfly species to evolve duller, less conspicuous wing coloration. However, the new analysis suggests that regardless of whether these animals change their coloration characteristics or not they will deal better with a warmer climate since many have already evolved an increased resistance to hot temperatures.
Predicting which species will be most threatened by extinction in an increasingly warmer world, requires understanding the intricate interplay between thermal tolerance and reproductive traits. By studying how animals respond to their environments with a more holistic perspective, researchers can develop better tools for conserving biodiversity in a rapidly changing climate.
