Tuesday, May 08, 2007


Dog Repeatedly Bites Casey Luskin

NEWSFLASH! ID's prediction that the sun will rise this morning is confirmed!
Casey Luskin is at it again! Luskin notes a report that:

Large swaths of garbled human DNA once dismissed as junk appear to contain some valuable sections [specifically, certain transposons], according to a new study by researchers at the Stanford University School of Medicine and the University of California-Santa Cruz.
Then he opines, from the vantage point of his great experience in science, that:

... it has taken scientists decades to investigate and validate this function -- a lot longer than it should have ... [because] this idea was stalled out due to the evolutionary assumption, รก la Talk Origins, that they are nothing more than useless "intragenomic parasites." Yet it was as far back as 1990 that pro-ID scientist and Discovery Institute fellow Forrest Mims had warned in a letter to Science against assuming that "junk" DNA was "useless"...
Now, I freely admit that I don't understand transposons but, unlike the people who Luskin hopes to fool, I can read the article from the Talk Origins Archive and am willing to make the effort.

First of all, the point of a prediction in science is that it has to confirm something that either was previously unknown or something that is in contradiction to an opposing theory. You couldn't choose between Ptolemy's and Copernicus' theories based on the sun appearing to rise in the morning.

In the section of the article Luskin points to from the Talk Origins Archive, Doug Theobald's "29+ Evidences for Macroevolution," Doug is discussing the molecular evidence for common descent. As he states: "finding the same transposon in the same chromosomal location in two different organisms is strong direct evidence of common ancestry, since they insert fairly randomly and generally cannot be transmitted except by inheritance." He then goes on to explain that the potential falsification of transposons as evidence for descent is the same as for pseudogenes:

... confirmation and potential falsification are independent of whether a specific pseudogene has a function or whether it is completely non-functional, for the same reasons explained in the prediction on morphological vestiges. Like any other genetic element or organismic structure, evolutionary opportunism may take a pseudogene and press it into a new and different function.

Thus, there was no "evolutionary assumption" that transposons would have no function. Indeed, Gill Bejerano, one of the authors of the study quoted in the Science Daily report clearly shared the hypothesis Doug Theobald laid out without it interfering in his work:

[Bejerano] suspects that when a transposon is plopped down in a region where it wasn't needed, it slowly accumulated mutations until it no longer resembled its original sequence. The genome is littered with these decaying transposons. When a transposon dropped into a location where it was useful, however, it held on to much of the original sequence, making it possible for Bejerano to pick out.
In other words, evolutionary theory does not predict in any sense that transposons will be funtionless, so what some crank once said, without any evidence to back it up, about "junk DNA" lends no support to ID over evolution. And the still-valid evidence that transposons give for common descent in no way retarded the discovery of the function that some of them may have.

But here's a prediction of my own: the region above Casey Luskin's neck will remain functionless for the foreseeable future.
Via The DesignInterference.
Oh, and as Mark Hoofnagle points out at denialism blog, Casey's own quote (in a part I didn't include for brevity's sake) shows that evolutionary biologist and Nobel laureate Barbara McClintock, who first discovered transposons, was proposing as far back as 1956 that they had function. Talk Origin's time machine allowed Doug to go back and stifle McClintock, apparently.

Luskin sez:

Yet it was as far back as 1990 that pro-ID scientist and Discovery Institute fellow Forrest Mims had warned in a letter to Science against assuming that "junk" DNA was "useless"


Oh wait, biologists were predicting functions for "junk DNA" back in the 60s. T.R. Gregory has more here:

I like this part from Gregory's article:

However, extrapolating each report that a given small segment of DNA may be functional to mean that all non-coding DNA is vital is as counterproductive as dismissing non-coding DNA as totally non-functional. Genomes are complex, and there is little use in approaching them from a simplistic point of view.

If the DI didn't have simplistic, they wouldn't be simps at all ...
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