the evolving mind

Any observer of nature will have noticed that many of the males are so colorfully “dressed” they seem ready to enter a gay pride parade. Or something. It was originally assumed that males do this largely to impress the ladies. And maybe by broadcasting their extreme manliness, to scare off competing males.

Recent research has discovered another reason for the secondary sexual characteristics that result in bright male coloration and exaggerated physical traits. And, surprise, it is not about sexual selection, about signaling health and fertility to the opposite sex. Rather, there is some male-to-male signaling going on. But here’s the wonderfully strange and new element: It seems by being brightly colored, males of one species are sending signals to males of another species.

Huh? But wait, before you conclude something kinky is going on, check out what researchers Gregory Grether and Christopher Anderson concluded from their study:

We found that male Hetaerina damselflies use species differences in wing coloration to distinguish between intruders of their own species and intruders of other damselfly species, but only at sites where the two species naturally occur together,” he said. “This provides one of the clearest demonstrations yet of an evolutionary process that is probably very prevalent in nature but which has largely been overlooked.

Well that make sense. A male wouldn’t want to waste its time and energy fighting off another male of a different species. For that male poses no real threat to its sexual reproduction.

Will their finding hold up for other species? The authors speculate about birds -

The cost of attacking the wrong type of male and of being attacked by the wrong type of male favors the rich diversity of coloration and of birdsong and chemical cues, such as odors, to identify rivals.

Makes sense. But is it true? Stay tuned. Thanks to science, we may soon find out.

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