Here's your infrequent, selected peep into the wile and wild world of insex*, this time, with the ever sparkly firefly (NY Times Science):
The fireflies flashing in the air are all males. Down in the grass, Dr. Lewis points out, females are sitting and observing. They look for flash patterns of males of their own species, and sometimes they respond with a single flash of their own, always at a precise interval after the male’s. [...] As adults, the earliest fireflies probably communicated with chemical signals, the way some firefly species do today. Only much later did some firefly species gain through evolution the ability to make light as adults. Instead of a warning, the light became a mating call. (An enzyme in the firefly’s tail drives a chemical reaction that makes light.) The more Dr. Lewis watched firefly courtship, the clearer it became that the females were carefully choosing mates. They start dialogues with up to 10 males in a single evening and can keep several conversations going at once. But a female mates with only one male, typically the one she has responded to the most.
The female fireflies turned out to be remarkably picky. In many cases, a male flash got no response at all. In some species, females preferred faster pulse rates. In others, the females preferred males that made long-lasting pulses.
Somehow, mating with males with certain flash patterns allowed females to produce more offspring, which would inherit their preference. It is possible that females use flashes to figure out which males can offer the best gifts. In many invertebrate species, the males provide females with food to help nourish their eggs. Dr. Lewis and her colleagues discovered that fireflies also made these so-called nuptial gifts — packages of protein they inject with their sperm. [...] In at least some species, females may use flashes to pick out males with the biggest gifts.
It turns out that a male firefly does not need to burn many extra calories to make flashes. [...] If making light is so cheap for males, it seems odd that they have not all evolved to be more attractive to females. “What is it that keeps their flashes from getting longer and longer or faster and faster?” Dr. Lewis asked.
Photuris kills other fireflies only to retrieve bad-tasting chemicals from their bodies, which it uses to protect itself from predators. [...] The scientists found that Photuris was more likely to attack when flash rates were faster. In other words, conspicuous flashes — the ones females prefer — also make males more likely to be killed. “At least where Photuris predators are around,” Dr. Lewis said, “there’s going to be a strong selection for less conspicuous flashes.”
*I will not charge for this clever word use. This time.
4 comments:
Aww, this reminds me that I saw fireflies the last night in NYC, when I was in Central Park. Mating call or warning, it's pretty magical. I saw some more, even while driving, the last few days of the road trip too.
I hadn't seen fireflies since I was a kid with my family on vacation in France, we don't have them this far up north. :(
Who knows what MASSACRE occurred that night for your enjoyment. Poor fireflies. :(
It's the sacrifice that had to be made in the name of getting some BOOTAY.
A firefly massacre in exchange for some bootay. You got your priority straight! That must've been some bootay. :deal:
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