Still Evolving After All These Years

The article in consideration is by Nicholas Wade, NYT, front page below the fold, March 7th, headlined: Still Evolving, Human Genes Tell New Story; given to me by a friend who said it made him feel good to know we weren't just standing still. --It's hard to critique jello. It wobbles and has a flavor but no discernible structure. I see nothing solid in this article, I do see the wobble and it does have a certain flavor.

First I quote, completely, the entire portion of the article that may be solid science.

• "...researchers have detected some 700 regions of the human genome where genes appear to have been reshaped...." &
• "The selected genes turned out to be quite different from one racial group to another. Dr. Pritchard's test identified 206 regions of the genome that are under selection in the Yorubans, 185 regions in East Asians and 188 in Europeans." There were "few overlaps" between races.

That's it for the science. Everything else is story telling.

The methodology as I understand it is this: The genomic map is examined. Tiny spots of variation are detected that exist within otherwise homogenous populations. Because these areas are not universal they are considered of interest.--It is highly highly doubtful that these researchers have any precise idea of what genetic function these tiny variations have.

But you can do a lot with a variation if you've got the right mind set. The theory is this:

"...the test for selection rests on the fact that an advantages mutation is inherited.... If the improved gene spreads quickly, the DNA region that includes it will become less diverse across a population because so many people now carry the same sequence of DNA units at that location." The more quickly a gene spreads, the more essential its mechanism, and the mechanism is that "Under natural selection, beneficial genes become more common in a population as their owners have more progeny."

So there you have it. For these variations to thrive, in effect those without them --700 in this study alone-- have to be killed off because they just can't compete for progeny. Genes affected include "skin color [&] hair texture". Does anybody believe a population is going to die out because of defective hair texture?

Now, the argument is made that these changes are "functional". That argument is made because otherwise the argument for natural selection is self-evidently silly. But as I've said, it's highly highly doubtful that the protein expression of any of these detected gene variations is precisely known, so the argument that they're significantly functional (all gene expression by definition is functional) is not based on evidence but on the initial presumption necessitating that they must be significant because otherwise there's no way they could spread rapidly through a population by natural selection.

I await more lab testing as to their specific functionality. It won't happen.

One interesting note. Some months back Dr. Bruce Lahn got all sorts of headlines when he reported that "evolutionary" changes in certain microcephaly genes explained the advent of agriculture and cities and perhaps of literature and high culture. "Dr. Prichard's test did not detect a signal of selection in Dr. Lahn's two genes..." Ah! So science is self-correcting... Well, not between gentlemen. As the quote continues "...but that may just reflect limitations of the test, he and Dr. Lahn said."

So there you have it. What ever evidence there might be out there for anything, by golly we are still evolving.

This is an area of study that should be interesting. unfortunately the only thing we know for sure that isn't evolving is the preconceptions of the people who write these papers.