Tuesday, August 28, 2007

"Evolution Can't Produce New Information"

From the Answers in Genesis website. I've provided the link to the original document, so you know this is not out of context:

"In response to 'Intelligent design an unproven theory' (March 17), it’s amazing that the writer’s evidence for evolution—'antibiotic-resistant' TB strains—is actually one of the best evidence against evolution.

A population of microbes becomes resistant to antibiotics because of a loss of genetic information or a transfer of information between microbes. But in no case have bacteria become resistant through a gain of new information."

I could respond to this the way Richard Dawkins did; but that'd be no fun. Instead, I'm going to warm up with some beneficial gene duplications, and then show you evidence against this claim using the strictest definition of information possible: A beneficial addition to the genome not involving gene duplication.

Alright, let's consider Richard Dawkins' answer: Natural Selection always increases the information of the genome because that's exactly what it does. What he means is that beneficial traits are favored while harmful ones are not, and thus the useful content of the genome increases. This could be illustrated with the evolution of the finch's beak, and how the average size grows and shrinks through different seasons. If you're familiar enough with evolution, you will remember how the Finches showed signs of speciation, and how it influenced Darwin.

Now let's move on to look at some gene duplications that have been beneficial. Gene Duplication is when a gene is mistakenly copied and inserted elsewhere in the genome. A duplicated gene can start off being the same as its parent gene, and then gradually be 'tweaked' to fit its new function. Since it can increase fitness, I would consider it 'new information'; though many creationists have argued it isn't because it is copying from something already there. Let's look at a few ways that it has been observed to be beneficial:

* Two enzymes in the histidine biosynthesis pathway that are barrel-shaped, structural and sequence evidence suggests, were formed via gene duplication and fusion of two half-barrel ancestors (Lang et al. 2000).

* Yeast was put in a medium with very little sugar. After 450 generations, hexose transport genes had duplicated several times, and some of the duplicated versions had mutated further. (Brown et al. 1998)

From Talk Origins

* Evolution of antifreeze glycoprotein gene from a trypsinogen gene in Antarctic notothenioid fish
Freezing avoidance conferred by different types of antifreeze proteins in various polar and subpolar fishes represents a remarkable example of cold adaptation, but how these unique proteins arose is unknown. We have found that the antifreeze glycoproteins (AFGPs) of the predominant Antarctic fish taxon, the notothenioids, evolved from a pancreatic trypsinogen. We have determined the likely evolutionary process by which this occurred through characterization and analyses of notothenioid AFGP and trypsinogen genes. It is first clear example of how an old protein gene spawned a new gene for an entirely new protein with a new function.

Now, for the final blow to AiG's desperate argument. An Insertion Mutation
is when a piece of DNA is added to the gene, increasing the number of characters. So, if I can just scratch up a couple of examples of this contributing a beneficial new function, then AiG's ultimate argument bites the dust.

Here they are:
From my other blog, Gill Slits

"E. Coli bacteria require 2 mutations in order to utilize salicin. In a lab, these two mutations were observed to occur and produce a strain of E. Coli that utilized Salicin.

'In growing cells the two mutations occur at rates of 4 x 10(-8) per cell division and less than 2 x 10(-12) per cell division, respectively.'

That's pretty heavy odds, right? So I wonder how it could have been observed... Well, Another paper which cited this one stated that mutations occur at higher rates in stressful environments."

Then there's the famous case of the nylon bug. A bacterium gained the ability to digest nylon via an insertion mutation, and is now thriving around nylon plants. AiG has tried hard to dispute this, but Talk Origins took them up on this and put them in their place.

A couple of interesting links:
http://www.msu.edu/~sharrowr/naturalselection.html
http://www.gate.net/~rwms/EvoMutations.html
http://www.pandasthumb.org/archives/2007/08/erv_hiv_versus.html

1 comment:

Dale Husband said...

I just posted a statement on this matter:
http://circleh.wordpress.com/2007/09/16/the-possible-role-of-nondisjunction-in-evolution/