WARNING: Do not tell your fundamentalist/creationist friends this news unless you want to watch their heads explode from all the cognitive dissonance.
It seems that crickets, the noisy little buggers you hear at night throughout this great land of ours, have either been blessed with a genuine act of GOD, or once again have provided more evidence that Darwin's "theory" of evolution (as amended over time by biologists) just might accurately describe how species change over time. Specifically, crickets in two separate places have either been told to "shut it" by God (hey miracles could happen I suppose, but crickets?), or they evolved to no longer make a joyful noise unto the Lord to protect themselves from predators. From the BBC News [ http://www.bbc.com/news/science-environment-27592656 ] online:
To hide themselves from deadly flies, crickets on two Hawaiian islands have evolved an inability to sing.
Ten years ago, two years apart, males appeared on Kauai and Oahu with altered wings, which they would normally rub together to chirp and attract females.
You see, the recent arrival of a particular fly species from North America proved deadly to the crickets on these Hawaiian islands. The flies were exceptionally good listeners. Able to pinpoint the location of the crickets by sound alone, the flies would drop in and lay baby maggots atop the male cricket's body. Once those little maggots got to work, well, that was all she wrote for the poor male crickets. In about than a week, give or take a few days, the crickets were eaten out husks of their former selves. This obviously forced the crickets to adapt or die out. And "adapt" they did, in fairly quick fashion.
In less than 20 generations, a mutation that leaves males unable to sing spread to over 90% of the crickets on the island of Kauai. [...]
Two years after the Kauai discovery in 2003, flatwing crickets were also found over 100km away on Oahu.
What's even stranger (or not) is that these Hawaiian male crickets on these two islands were "silenced" as it were by two separate mutations according to a study published in the journal "Biology" (citation: S. Pascoal et al., “Rapid convergent evolution in wild crickets,” Current Biology, doi:10.1016/j.cub.2014.04.053, 2014 [ http://www.cell.com/current-biology/abstract/S0960-9822(14)00524-7 ]); apparently these mutations happened completely independently of one another:
The idea that the trait had evolved twice, at almost the same time, seemed far-fetched. "It still seems amazing to me," Dr Bailey told BBC News.
The first clue was an observation that the mutant, silenced wings on the two islands had two different shapes. [...]
[C]omparing a raft of other genetic markers between the two groups yielded convincing evidence that the two mutations had occurred independently.
Can't wait to hear what explanation the Creationists have for God deciding to cause separate mutations to these Hawaiian crickets to achieve the same result: keeping them quiet. I suspect in this case, we won't even hear the crickets in their response.
Two island populations of male crickets independently evolved to evade parasites by keeping quiet, and have come up with a way to sneak matings with females that still seek the male courtship song.
By Sandhya Sekar | May 29, 2014
As the sun sets over the grassy lawns that traverse the Hawaiian island of Kauai, the chirping crickets do not perform their usual dusk chorus. Instead, they are ominously quiet: in Kauai and neighboring Oahu, field crickets (Teleogryllus oceanicus) have acquired a wing mutation that silences them. It also saves them from being eaten inside out while still alive.
The field crickets in Kauai offer a live demonstration evolution in action. In 1991, cricket numbers crashed as parasitoid flies (Ormia ochracea) located male calling crickets by sound and made them into hosts for their larvae. The parasitic larvae would burrow into their cricket hosts and eat them from the inside out. Twelve years and 20 generations later, the cricket population bounced back, dominated by males with a wing mutation that rendered them silent. Male crickets on Oahu followed suit within two years; eventually, silent males outnumbered their chirping peers.
Sonia Pascoal [ http://biology.st-andrews.ac.uk/contact/staffProfile.aspx ] from Scotland’s University of St Andrews and her colleagues sought to investigate how the mutation in the wing for silent males, called “flatwing,” might have spread from Kauai to Oahu. Two possibilities stood out: silent males may have hitched a ride from Kauai to Oahu, where the flatwing mutation took hold through a process called introgression, or the mutation evolved independently on each island.
The researchers found that the vein patterns in the wings of the silent crickets in Kauai were strikingly different from the patterns observed in Oahu. The Kauai flatwing mutants exhibited a more drastic loss of wing structures necessary for chirping. Single nucleotide polymorphism analyses showed that each island had its own set of unique markers, with just a 0.3 percent overlap. At the same locus, different alleles were responsible for the flatwing mutation in the two islands. Both morphological and genetic analyses suggested that the flatwing mutation evolved independently in the two populations.
“The wing mutation may have knock-on effects . . . that cause other changes,” Bailey told The Scientist in an e-mail. “We are generating data examining this question, by looking at cuticular hydrocarbons and other traits.”
Of course, parasitoid flies are not the only ones who rely on chirps to locate male crickets—female crickets find mates through their calls. So how were the silent males managing to mate with females?
By exploiting wild-type, chirping males. The researchers found that the silent male crickets placed themselves less than a meter from a cricket song and accosted females as they made their way to the calling male. Female crickets on Kauai also seemed less choosy; usually, females choose a male by his courtship song, which silent males cannot provide.
Whether the silent bystanders are successful in getting free rides is something the group will work on next. “Our collaborators are currently comparing the fitness of the silent and loud males by analyzing patterns of mating in the field and in controlled laboratory trials,” said Bailey.
“I would predict that males in the affected populations would, in the near future, evolve to invest more in the other forms of sexual advertisement . . . instead of acoustic sexual signaling,” Raine Kortet [ http://wanda.uef.fi/biologia/kortet/index.html ] from the University of Eastern Finland, who has worked on crickets from Hawaii but was not involved with this study, wrote in an e-mail. “It is already known that field crickets from the family Gryllidae use pheromonal cues in their mate choice.”
While they’re less likely to be found, silent males are not immune to attacks by parasitoid flies. Once, when Bailey and Pascoal were observing crickets from Kauai in he field, they saw “a mature larva writhed out of a flatwing male's abdomen before our very eyes,” said Bailey.
“I think these fascinating studies provide convincing evidence that the evolution of silent males has been favored by the presence of the acoustically orienting parasitic fly,” said Tom Tregenza [ http://biosciences.exeter.ac.uk/staff/index.php?web_id=tom_tregenza ] from the University of Exeter, U.K., who was not involved in the study. “I suspect that there may be other examples of the same phenomenon waiting to be discovered. The difficulty is that you can’t listen for silent males.”