Seth Shostak of the SETI Institute has written an article on SETI and Intelligent Design, detailing the difference between SETI and Intelligent Design. He notes that intelligent design proponents have offered SETI’s methodology of detecting design as evidence that intelligent design is scientific. He then proceeds to respond to that claim.
There are several problems with his article, some of which I will address here, in quote-and-reply fashion.
As just about everyone is aware, these folks use similar logic to infer a "designer" behind such biological constructions as DNA or the human eye. The apparent complexity of the product is offered as proof of deliberate blueprinting by an unknown creator--conscious action, presumably from outside the universe itself.
Complexity (or, more specifically, linear complexity) may be defined as randomness [Li and Vitanyi; Yockey 1992].
To quote Abel (2009),
“A random string is the most complex because its sequence cannot be enumerated using any algorithmically compressive string shorter than itself. Notice that this precise definition of linear complexity has nothing to do with meaning or function.”
So, Seth Shostak is wrong when he claims that “the apparent complexity of the product is offered as proof of deliberate blueprinting by an unknown creator.” Complexity in itself is not offered as evidence of intelligent design in a given biological system. A random string of nucleotides is complex but it can be easily explained as the result of random mutations; in such a case, intelligence is not a more adequate explanation for the origin of that random string of nucleotides.
The way this happens is as follows. When ID advocates posit that DNA--which is a complicated, molecular blueprint--is solid evidence for a designer, most scientists are unconvinced. They counter that the structure of this biological building block is the result of self-organization via evolution, and not a proof of deliberate engineering. DNA, the researchers will protest, is no more a consciously constructed system than Jupiter's Great Red Spot. Organized complexity, in other words, is not enough to infer design.
The problem with this paragraph, of course, is that intelligent design proponents do not infer design on the basis of organized complexity. Complexity in itself really isn’t part of the equation in the detection of intelligent design. Nor is organization. A cube that is exactly 10 in. x 10 in. x 10 in. is not complex, and it is not organized either, but it is indicative of intelligent design (a la Dr. Sean Pitman). In brief, intelligent design proponents do not infer design on the basis of complexity or organization.
In fact, the signals actually sought by today's SETI searches are not complex, as the ID advocates assume.
We don’t assume that the signals SETI researchers are looking for are complex.
A SETI radio signal of the type we could actually find would be a persistent, narrow-band whistle…. And yet we still advertise that, were we to find such a signal, we could reasonably conclude that there was intelligence behind it. It sounds as if this strengthens the argument made by the ID proponents. Our sought-after signal is hardly complex, and yet we're still going to say that we've found extraterrestrials. If we can get away with that, why can't they? Well, it's because the credibility of the evidence is not predicated on its complexity.
In that last sentence lies the fatal flaw in Shostak’s line of argumentation. In the case of intelligent design, the credibility of the evidence is not predicated on its complexity. The word “straw-man” immediately comes to mind.
If SETI were to announce that we're not alone because it had detected a signal, it would be on the basis of artificiality. An endless, sinusoidal signal - a dead simple tone - is not complex; it's artificial. Such a tone just doesn't seem to be generated by natural astrophysical processes.
We’re on to something now. Intelligent design proponents use the exact same methodology:
If intelligent design proponents were to announce that a certain biological system was intelligently designed, it would be on the basis of artificiality (whatever “artificiality” is supposed to mean). A biochemical system that cannot be explained by Darwinian processes is not necessarily complex (and let’s not forget how “complexity” is defined). Such a biological system just doesn't seem to be generated by Darwinian processes.
In addition, and unlike other radio emissions produced by the cosmos, such a signal is devoid of the appendages and inefficiencies nature always seems to add - for example, DNA's junk and redundancy.
Note the phrase “nature always seems to add.” The intelligent designer(s), for example, could have designed the flagellum, and afterwards “nature” added other components which made it less efficient.
So that's one point: the signals SETI seeks are really not like other examples drawn from the bestiary of complex astrophysical phenomena. That speaks to their artificiality.
So that's one point: the biological systems with which intelligent design proponents infer design are really not like other examples drawn from the bestiary of complex Darwinian phenomena. That speaks to their artificiality.
In summary, SETI detects intelligence behind a radio signal on this basis,
(1) The signal is not known to be generated by natural astrophysical processes.
(2) The signal is produced by human intelligence.
(3) Also, context (i.e., where in the universe the signal is found). However, this is irrelevant to the field of intelligent design, since it would be difficult to imagine what would be an appropriate “context” to determine that the flagellum was intelligently designed.
Intelligent design proponents detect intelligent design in biological systems on this basis,
(1) The biological system is not known to be generated by mindless processes.
(2) The signal is known to be generated by human intelligence.
Why would a radio signal consisting of a string of the first 100 prime numbers be indicative of an intelligence, as suggested by Seth Shostak? It is because,
- There is no known mindless process that can explain the origin of such a radio signal,
- There is a known intelligent mechanism that can explain the origin of that radio signal.
And this is exactly the same methodology intelligent design uses to detect design in biological systems.
Li, M.; Vitanyi, P. An Introduction to Kolmogorov Complexity and Its Applications, 2nd Ed.
Yockey, H.P. Information Theory and Molecular Biology. Cambridge University Press:
Cambridge, 1992; p. 408.
Abel, David L. The Capabilities of Chaos and Complexity. International Journal of Molecular Sciences, 10(1): 247-291(2009).