Tuesday, 28 August 2007

Peppered Moths

One of the finest examples of evolution is the Peppered Moth or Biston betularia. In fact it is so great that I am learning about it again in first year Biology. This is also the first post that I have written discussing Creationism so I hope I don't stuff this up.

Now I don't know if I can really say that I love Biology, I must admit that I prefer Chemistry but for me to live up my dream I need to understand something about Biology anyway.

Now for those that don't know the Peppered Moth (I prefer the common name, less italics to write in) can be found in the UK and can be found in two varieties a melanic variety (which is dark) and a lighter form.

Although the experiment undertaken by Bernard Kettlewell in the 1950's the effect started from the beginnings of the Industrial Revolution.

Before the huge increase in factories the forests were clean and had light coloured lichen growing on the trees.

The lichen allowed the lighter moths to survive easier compared to the melanic ones because they could easily camouflage themselves on the trees and not get eaten by the birds that preyed on the insects.

Naturally the darker moths were easier targets and were eaten.

However the Industrial Revolution changed the rules.

The drastic increase of factories spewing out smoke created plenty of soot that killed off the lichen and covered the trees in black soot.

The colours of the moths changed. The melanic moths started to become more common, not being the rare variety anymore but the common one.

Kettlewell managed to show in his experiment that the darker moths were prevalent because the birds found it harder to find them in the soot covered forests.

After the 50's with a program that cut down pollution they found that the moths returned to their original colour diversity.

Now creationists seem to have a problem with this trying to find ways of disproving the hypothesis. The Panda's Thumb mentions them claiming that the results were "faked" and Talk Design has an article that quite thoroughly shows how first the creationists are wrong and how the book Of Moths and Men is also wrong.

This site which is probably getting more exposure then it should, says the following:

IMHO...a couple of issues with the most recent peppered moth study. It's still a moth, and the evolution is an oscillation of populations, just like the finches of Galapagos. Of course, the Darwinists will appeal to the "great creators", random chance, natural selection, and the jackpot, hundreds of millions of years. Given enough time, anything can happen, right?

What we see here is what we can call 'a quite stupid comment'.

It isn't the worst that I have heard from a creationist. The number one thing is a tie between someone claiming that macroevolution was "a rock turning into a banana" or "the Peppered Moth isn't an example of evolution because the pollution was man made but evolution is natural"

Trying to claim that the Peppered Moths has nothing on evolution because it is "still a moth" is a moot point. What was shown here was that the moths adapted to survive, those that were born melanic in a dark environment meant that they were more likely to survive.

The evolution was not just an "oscillation of populations" it was an increase/decrease clearly in the allele frequency of the population. Which, anyway, has nothing in common with the Galapagos finches. The Galapagos finches arrived on the island, most likely from a storm on the mainland and over time they reproduced but they also filled unfilled niches in the ecosystem. The one that I can think of at the moment is the Warbler Finch which is a finch that has adapted itself into a type of warbler, but it is still a finch.

The next line of that comment is just standard creationist drivel, make it sound like a religion and somehow it becomes an idea that is characterised by a belief system but clearly shows a lack of understanding of evolution.

Random chance only affects life if it is something that does not target specific species, for example an asteroid hitting the Earth. It doesn't discriminate between a fit animal and an unfit animal it just kills and whatever manages to survive is bloody lucky.

What he calls the "jackpot" (millions of years") is not always the case. It does not take millions of years for bacteria to become resistant to types of medicine, nor does it take millions of years for various species to become immune to the effects of bacteria like Wolbachia.

To finish, what makes creationists funny (or even IDers) is that they try so hard to disprove something but they don't understand the thing they are trying to disprove, so they fall back to fallacies...

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