I do not read the intelligent design blogs, but I do read the blogs of some people who read the intelligent design blogs. Today, Afarensis points to a series of “predictions” put forward by ID proponents at the behest of William Dembski on his blog Uncommon Descent for use in an upcoming interview or something. Curious to see what ID predicts (since, as noted, I don’t read their blogs and they don’t publish in the scientific literature), I took a look.
Apparently, many ID proponents don’t know what a prediction is, or at least not what a useful, testable, scientific prediction is. For example:
“Intelligent design can predict that science will never be able to explain how this complex life arose (homochirality). This prediction has been confirmed every year for decades.”
“That after â€œbillions and billionsâ€ of generations of any particular biological entity no new morphology will occur due to random mutations and natural selection.”
“ID predicts that many, if not all, innovative technology achievements of human kind (read agency) will have direct parallels in, or derivation from, biological systems.”
And so on.
But here is what caught my attention.
“The single most important prediction of Intelligent Design is that, although there might be the occasional degeneration of either macroscopic or microscopic structure, most structures should serve a purpose. Thus most organs should not be vestigial, and most DNA should not be â€œjunk DNAâ€.”
Others concurred that 1) junk DNA won’t be junk, and 2) this is a prediction of ID, and 3) this distinguishes ID from evolutionary science.
1) There is good reason to believe that non-functional DNA is common. The mechanisms of formation — primarily things like transposable element multiplications, gene duplication and pseudogenization, replication slippage, and unequal crossing over — can add DNA without any requirement that it serve a function. Actual data from genome sequences confirms that the most substantial fraction of eukaryotic DNA is transposable elements, some of which are functional, some of which cause disease, and perhaps most of which are now inactive molecular vestiges. Evolutionary biologists do not simply assume non-function out of ignorance. The default assumption for much non-coding DNA is non-function because of what we do know about how it gets there.
2) I have yet to see a convincing, or even unconvincing, argument for why ID requires that non-functional features be rare or non-existent if indeed nothing can be known about the designer. Even very sophisticated products of design by humans have their redundancies and non-functional aspects. For a fun example, consider what was discovered when parts of the source code for Windows 2000 were leaked to the internet during development. It was laced with curse words, warnings of “hacks” that had to be written in to make parts work, and just general expressions of frustration. For example:
“ // We are morons. We changed the IDeskTray interface between IE4″
“ // TERRIBLE HORRIBLE NO GOOD VERY BAD HACK“
“ * The magnitude of this hack compares favorably with that of the national debt.”
“ // Mondo hackitude-o-rama.”
These are remarks that do not code for anything. You could take them all out and nothing would happen to the function of the software. Or, taking a larger view of this analogy, your computer hard drive probably has on it all sorts of redundant, partly deleted, or perhaps even malevolent bits of code, and yet it nonetheless was a designed structure.
Here is the argument I am making. Either IDists cannot say anything one way or the other about non-function, or they must provide information about the method and motive of the designer to justify the assumption.
3) One of the basic assumptions made by hardcore adaptationists is that non-coding DNA must be functional or it would have been deleted. So, this “prediction” is not exclusive, or even original, to ID — it is based firmly in the most rigid applications of Darwinian processes.
One commenter on the ID blog said this:
“As already mentioned, â€œjunk-DNAâ€ would completely undermine ID if it turned out to really be â€œjunkâ€. But, of course it isnâ€™t.”
I disagree on both fronts. The existence of truly non-functional DNA would not automatically indicate a conclusive refutation of intelligent design, it would only be evidence against design by a divine designer. One can have design with non-function. I also note that there presently is no convincing evidence that more than a small portion of the human genome is functional, let alone the many genomes that are much larger than that of humans.
IDists can consider “all or most non-coding DNA will have some function” their “single most important prediction” if they choose, but this is meaningless because it provides no specifics, it does not actually allow a test of ID unless they acknowledge the features of the designer, and it was already made by some evolutionary biologists decades ago.