Submitted by Waspie Dwarf: Scientists say they have seen one of the fastest evolutionary changes ever observed in a species of butterfly. The tropical blue moon butterfly has developed a way of fighting back against parasitic bacteria. Six years ago, males accounted for just 1% of the blue moon population on two islands in the South Pacific. But by last year, the butterflies had evolved a gene to keep the bacteria in check and male numbers were up to about 40% of the population. Scientists believe the comeback is due to "suppressor" genes that control the Wolbachia bacteria that is passed down from the mother and kills the male embryos before they hatch. "To my knowledge, this is the fastest evolutionary change that has ever been observed," said Sylvain Charlat, of University College London, UK, whose study appears in the journal Science. Gregory Hurst, a University College researcher who worked with Mr Charlat, added: "We usually think of natural selection as acting slowly, over hundreds of thousands of years.

"But the example in this study happened in the blink of the eye, in terms of evolutionary time, and is a remarkable thing to get to observe." The team first documented the massive imbalance in the sex ratio of the blue moon butterfly (Hypolimnas bolina) on the Samoan islands of Savaii and Upolu in 2001. In 2006, they started a new survey after an increase in reports of male sightings at Upolo. They found that the numbers of male butterflies had either reached or were approaching those of females.

View: Full Article | Source: BBC News

Odd... and why don't they think this is merely an example of survival of the fittest? It's really quite clear that not all males were killed, so either some weren't exposed, and somehow they decided they needed to evolve to counter something they hadn't experienced, or some males have always had the resistance to the bacteria. Now the ones that didn't have that resistance are dead.

I'd believe it was evolution if I was inclined to believe fairy tales...

Evolution is not the survival of the fittest but the survival of those most adaptable to change. Getting a bacterial infection is change. Getting resistant to a bacterial infection evolution as scientists define it.

that means that you believe a butterfly not able to survive the bacteria did not encounter the bacteria yet evolved to defeat the bacteria it had not encountered?? LOL

I suppose you also believe the black moth white moth incident was evolution as well?

No. Most likey what happened was the 1% of butterflies that were alive carried the gene that saved it from the bacteria. They were able to survive and therefor pass on thier DNA to later generation. It's not the butterflies never encountered the bacteria; they did, they survived.

So you're saying it was not a gain in genetic info, but a loss? That those who had a different genetic makeup died out and the species now has less variety?

Edit: Sounds more like devolution than evolution to me.... but that same devolution is apparent all over the earth.

JS

Which is also part of evolution. If you need to survive by going two steps backwards the species will, see the Flores man or the dolphin.

regress is a part of progress?

And here is what most people don't understand about evolution. It is not about progress, it is about survival.

Every organism pro or regresses as needed to occupy a niche that is left vacant in order to survive. Sometimes it displaces other organisms out of that niche.

The Flores man, for example is maybe the most drastic example of a regression, but not the only one.

If only we could start evolving. Some hope perhaps.