Climate change may be having effects far beyond its impact on the world's weather patterns; it may even be influencing the evolutionary progress of some of the globe's species, researchers say.
As temperatures increase, the European scientists have found, populations of dragonflies and butterflies are shifting to more lighter-color species.
Body color in some species, including insects, snakes and lizards, is a factor determining the amount of energy -- crucial to movement and regulating body temperature -- a creature can absorb from the sun, with darker colors absorbing more light and lighter colors reflecting it.
In a study of 366 species of butterfly and 107 species of dragonfly throughout much of Europe, the researchers discovered lighter insects were really becoming the majority in most southern areas while insects displaying darker colors were shifting their distribution north towards cooler regions.
"We now know that lighter-colored butterflies and dragonflies are doing better in a warmer world, and we have also demonstrated that the effects of climate change on where species live are not something of the future, but that nature and its ecosystems are changing as we speak," researcher Carsten Rahbek of the Center for Macroecology, Evolution and Climate at the University of Copenhagen said.
The finding of lighter colored species in the south and darker colored species in the north highlights the importance heat regulation plays in the health of the various species, he said.
"When studying biodiversity, we lack general rules about why certain species occur where they do," said researcher Dirk Zeuss from Philipps-University Marburg in Germany. "With this research we've been able to show that butterfly and dragonfly species across Europe are distributed according to their ability to regulate heat through their color variation."
Since insect colors are also a major factor in keeping them safe from predators by providing camouflage, the finding that the species composition of populations could be influenced by a single factor -- changing temperatures -- is significant, the researchers said.
"For two of the major groups of insects, we have now demonstrated a direct link between climate, insect color and habitat preference," said Rahbeck.
Such findings support the assertion that such geographical distribution changes, seen before in local-scale studies, are occurring on a continental scale, the researchers say.
Massive shifts in the distribution of many species have been observed for the last 2 decades, but the role of climate change has been difficult to pin down until the latest study, they say.
The study has been reported in the journal Nature Communications.
