I recently re-watched an old (April, 2006) Intelligent Design debate between Stephen Meyer and Peter Ward (you can find it online). The debate itself is not very balanced. Essentially Meyer gives a well-reasoned, thoughtful defense of ID for an hour and a half, and Ward interupts periodically to interject "It's not science". To racous applause, no less! It's not that Ward wasn't given equal speaking time, it's that he didn't really use his time to say much of anything with substance.

There is certainly a more convincing case to be made for evolutionary theory than Ward presents. What is really telling is the fact that he doesn't take ID seriously enough to think it worthy of any serious rebutal. Ward has serious academic credentials, but you would never know it from listening to the debate. He doesn't seem to think he needs to utilize them.

But what I really wanted to highlight is a clever argument which Meyer makes. He notes that Darwin and Charles Lyell (a geologist who had a major influence on Darwin) sought to explain their observations through "presently acting causes". The idea is that it is improper to invoke exotic causes to explain your observations. Observations should instead be explained by the forces which we see at work today.

Lyell was the first to explain geological formations by the accumulation, over long periods of time, of the processes of erosion which we observe today. Darwin sought to explain life the same way: as an accumulation of small, successive variations of the type observed by breeders (in fact, the very name "natural selection" was chosen because Darwin explicity compares it to artificial human selection).

Meyer takes this principle and extends it to information: we now know that living cells are the most complex machines on the planet, far outstripping anything that humans have designed and containing reams upon reams of digital information quite analogous to computer code. What, he asks, is the only presently acting cause of the sort of information that is found in computer programs? Intelligence! We observe that intelligence is capable of producing just exactly what we find in the cell. We observe that to get a complex new function out of an existing system, you must add code (information) via an intelligent agent. There is no evidence whatsoever that the near-limitless capacity for variation which Darwinian evolution requires is achievable through undirected processes. On those grounds we ought to prefer the presently acting cause, intelligent design, over exotic hypotheses about self-assembling molecules in the primordial soup, or the emergence of exquisite nanotechnology from random mutation.

William Bradford, over at Intelligently Sequenced, talks a lot about the evidence of design from cellular DNA repair mechanisms. The genomes of modern cells rely for their integrity on incredibly complicated methods of error-detection and repair. Focussing ID criticism here highlights a fundamental weakness in darwinian origin-of-life scenarios: In order for natural selection to improve a self-reproducing molecule, it must have a mostly reliable method of reproducing itself. Otherwise fit individuals would not be able to transfer their fitness to their descendants.

As we now know, it cannot just be taken for granted that a primitive cell (or even a pool of replicating rna) without repair mechanisms  could maintain its genetic information with enough accuracy to survive, let alone ensure that the descendants of fit individuals were likely to retain their parent's fitness advantage. This is a major obstacle to abiogenesis (as if spontaneously generating self-reproducing molecules wasn't hard enough :-).

Last year, I defined "isomorphic instantiation" as the phenomenon in which a complex technology developed by intelligence is subsequently found to exist in nature. In a sense, isomorphic instantiation is the inverse of biomimetics, since biomimetics is the discipline of making technology that mimics the marvels of nature.

We can see a example of isomorphic instantiation in a paper entitled "Biplane wing planform and flight performance of the feathered dinosaur Microraptor gui" published yesterday in the Proceedings of the National Academy of Sciences. If you don't have access to this paper, you can read news accounts. The paper suggests that the Microraptor had 4 wings in a configuration strikingly similar to the biplane. The authors conclude:

Aircraft designers have mimicked many of nature’s flight "inventions," usually inadvertently. Leading edge slats delay stalling, as does the alula of birds; birds’ feet act as airbrakes, and streamlining reduces drag. Now, it seems likely that Microraptor invented the biplane 125 million years before the Wright 1903 Flyer.

Isomorphic instantiation is a good indicator of intelligent design. We know that intelligent agents (namely, the Wright Brothers) invented the biplane. When a feature in nature, like the Microraptor's biplane wings, is strikingly similar to an invention already designed by intelligent agents, one must entertain the possibility that the feature in nature may have also been designed by an intelligent agent. We can't just automatically assume that complex technologies invent themselves. After all, did the Wright 1903 Flyer invent the biplane or did the Wright Brothers invent the biplane?

I recently ran across a paper with the intriguing title Evolution based on Design-by-Contract: Origin of Life through an abiotic double-stranded RNA world by Albert De Roos.

Design-by-Contract is a computer science methodology for keeping software easily maintainable and changeable by reducing dependencies. Essentially, it advocates treating functionally distinct blocks of code as black boxes. These code blocks define a specific set of methods (interface) which are "public". Other code blocks interact with it only through these specific methods. As long as the interface remains intact, the internals of the code are free to change radically without fear of introducing bugs.

The author draws an analogy to origin-of-life research, noting that while many people believe single-stranded RNA was the first self-reproducing molecule, the transition from single-stranded RNA to DNA faces significant problems:

It is difficult to imagine ssRNA to have a dual function since the catalytic properties of RNA depend on the three-dimensional structure, while the informational capacity would require a simple linear structure that can be replicated (Taylor, 2005). The folding of an RNA molecule would prevent its own replication, while for replication a folded ribozyme would be necessary... From a system perspective, a dual function in a single entity would create a dependency that would reduce evolvability of the system.

The author goes on to explain how double-stranded RNA might be changed into DNA through a process that maintains existing interfaces and requires fewer radical changes. Central to his thesis is the idea that RNA started out as an information-carrying molecule. This makes information a pre-requisite for any self-replication.

The paper doesn't make any mention of a designer, however. In fact it speculates about how self-replicating double-stranded RNA might have arisen on the early earth, and explains the gradual steps which the author claims are sufficient to transform double-stranded RNA into DNA. Does it count, then, as an ID paper? I think so. Modeling biological systems with engineering paradigms is an obvious application of ID. If this approach is fruitful, then ID will be a successful research program.