Wednesday, February 3, 2010

Epigenetics Anyone?

The newest wrinkle in the evolution wars is epigenetics. What epigenetics proposes is that we have mechanisms which decide how strongly a genetic trait is expressed. How strongly the trait is expressed is a result of, among other things, the experiences of the parent. So, a trait which an offspring inherits can, in one generation, be dramatically changed. This in contrast to the traditional Darwinian concept that change is more or less random.
If this is so (and information is sparse but persuasive), then evolution is not necessarily the slow, plodding, blind process that we have all thought it to be. It can operate much more swiftly than we could have imagined.
Some have written that this view supersedes Darwin. Au contraire, my friends. It adds to it, but the basics of Darwinian evolution, survival of the fittest, still rule. Nor can we say that the evolutionary theories of Lamarck have been vindicated. Lamarck, it will be remembered, thought that acquired characteristics could be passed on. If that were true, theorists say, Jewish males would long since have been born without foreskins.
Epigenetic theory proposes that the basic DNA doesn't change. What changes is the way it shows up in the finished product. This is exciting news indeed.

2 comments:

Jacqui Binford-Bell said...

This is going to take some thought. I was trying to apply it to suicide bombers. Darwin would say they do not pass on their genetic material so they are out of the evolutionary mainstream.

However, if parents want suicide bombers - if is indeed a desired trait - then they could flourish.

On both your houses said...

Actually, I think it's a little more complex, or simpler, I'm not sure which. Let's say that you have a gene for brown eyes (I'm simplifying here). Epigenetics suggests that conditions can influence the way that that brownness is expressed in a peson's offspring. Since being a suicide bomber is a very complex set of interactions, I don't think you can breed for them.