« Prev Next »
Now, with this in mind, imagine you are an insect. Since you are exothermic, you must rely on the
environment as your body’s heat source, and without this external heat source, you
would not be able to move, forage, mate, and function properly. But, as we all
know, too much of a good thing can turn out to be harmful in the end. What if
the temperature of your environment steadily rises, reaches a point that is too
high, and causes you to absorb excess energy and heat from the sun? You are now
faced with the threat of overheating and death. This is the problem that many
insects, which make up 80%
of all life on Earth, are now facing due to the ever-growing problem of
global warming.
A study
recently published in Nature Communications
addressed how some insects are coping with the rise in Earth’s temperature. Collecting
and analyzing data from 473 European species of butterflies and dragonflies,
the scientists found that these insects were becoming lighter in color over
time (1988-2006). Just as my white, summer shirt reflects more light than my black,
winter shirt, the insects with lighter colorations reflect more light than their
darker counterparts. In this way, they are protecting themselves against the threat
of overheating.
It was also observed that light-colored dragonflies and
butterflies are more prevalent in the southern regions of Europe, while the
darker ones are more dominant in the northern regions. This is because
darker-colored insects are seeking cooler places to avoid overheating. However,
whereas these dark-colored insects are better able to survive in the European
northern climates with lower temperatures, the researchers believe that light-colored
insects may be able live in a broader
range of habitats (in both the southern and
northern regions of Europe) because they are better able to regulate heat.
Therefore, the light-colored insects are out-competing the
dark-colored ones. This is a prime example of natural selection, and therefore,
overtime, we should expect to see a much greater percentage of light-colored
insects than dark-colored ones in Europe.
I find these color changes in the European butterflies and
dragonflies to be very interesting, because I never considered the effect one's color can have on one’s ability to survive. As the Earth’s temperature
continues to rise, it is crucial that other insect species and life forms find
ways to adapt to or cope with their new climate. If not, they are faced with the threat of eventual extinction.
What do you think of this direct trend between climate and
insect coloration and its impact on the insects’ geographical distribution?
For more reading on the effect global warming has on
butterflies, click here.
Picture Credit: Butterfly. Catlovers (via Flickr
and available for use under the CC License)
Sources:
Dirk
Zeuss, Roland Brandl, Martin Brändle, Carsten Rahbek, Stefan Brunzel. Global
warming favours light-coloured insects in Europe. Nature
Communications. 2014
Imperial
College London "Light-colored
butterflies and dragonflies thriving as European climate warms." ScienceDaily. 27 May 2014.
Wilcox, Christie “White
Hot Insects: Climate Change Leading to Lighter Colors” Discover. 27 May 2014.
