The Cricket and the Fly

Once upon a time on the magical islands of Hawaii, there lived many families of crickets. The males were known for their song. The Elvis and Frank Sinatra impersonators were the ones that got the girls. The quiet types sat by themselves, oh so sad as they rubbed their wings together in silence.

This was the way of the cricket world until one day an evil fly came to paradise. Trust me when I say this is one nasty beastie. If you have seen the movie Alien, then you know how this fly works its "magic." It lays eggs on the backs of poor unsuspecting crickets. Adding insult to injury, the eggs soon hatch and fly larvae burrow their way into their "host." A week later, a full grown fly climbs out of the empty cricket shell.

Here is the terrible irony. The evil flies have discovered the best way to find a cricket to serve as incubator is to listen for the chirp of male crickets singing for a mate. Before long the quiet type crickets are getting all the girls because the crooners are attracting flies.

Now the fields and forests of Hawaii are quiet. Cricket song has disappeared, replaced by dance in courtship rituals. As for the flies, they are flustered and wonder where all the crickets have gone.

This story just so happens to be true and is a very big deal in the scientific community. The scientists are chirping because there was a rapid shift in the cricket gene pool favoring flat wings which do not make a sound no matter how much they are rubbed together.

The change seems to have been caused by a mutation that altered the shape of their wings, making them incapable of producing the chirping noise. The feat was achieved over less than 20 generations, a mere evolutionary blink of an eye, and, with the crickets living just a few weeks, a very rapid process. By 2003, a study by Marlene Zuk at the University of California Riverside found that up to 95% of male crickets on Kauai were no longer able to chirp. The mutation had erased almost all the wing structures that help to make the sound, leaving the wings flattened but still airworthy. 

Just two years later, in 2005, male crickets on the island of Oahu, 101 kilometres from Kauai also began to fall silent. Today, about half of the males on Oahu are chirpless, Bailey has found.

This is evolution in action. A genetic mutation offers a better chance for survival, allowing a species to adapt to an emerging environmental threat. Then scientists discovered that lightening had struck in two different places at the same time.

In their study, published today in Current Biology, Bailey and his team analysed the genomes of crickets from both islands using a technique that slices DNA into small fragments and then detects hundreds of thousands of genetic markers, or small distinct regions of the genome. The genetic markers associated with the flat wing are very different in the Kauai and Oahu populations. “It means that different mutated portions of the genome cause males to be flatwing in either population,” says Bailey. 

This evidence suggests that the mutations happened independently on both islands, making the Hawaiian silent crickets “an excellent example of convergent evolution”, says evolutionary biologist Richard Harrison of Cornell University in Ithaca, New York.

I almost feel sorry for people who want to see creation as a static process that ended long ago. Since science undermines their faith, they are unable to see the hand of the Creator still at work in a system that promotes survival of species through dynamic interaction between genes and the environment. Instead of awe they are left with cognitive dissonance. Deliberate ignorance has a price. Claiming this planet is a few thousand years old despite overwhelming evidence to the contrary does not serve God.