Wednesday, January 21, 2009

Darwin Bicentenary Part 2: DaveScot, ID Guru, Speaks Out

In my last post I said of evolutionary theory: “As an explanation of the taxonomy of natural history there looks to be no other game in town that is as good”, the implication being that ID theory was not as good on this score. However some recent comments by DaveScot on Uncommon Descent are relevant in this connection and throw some light on how a well established ID theorist views this matter. It’s only fair that I set these comments against my own. Dave says;

My position, which has remained unchanged for several years, is that phylogenesis was a planned sequence. Common descent from one or a few ancestors beginning a few billion years ago has overwhelming evidence in support of it. Gradualism however does not have overwhelming evidence.

He also says:

No Darwinists I know or read give saltation any credence. The reason why is because saltation implies front loading.

My interpretation of all that is as follows. Dave accepts that a wide variety of species evolved from a single ancestor thus implying the clade structure of organic taxonomy. But rather than seeing evolutionary change in terms of the gradualism of standard Darwinian Theory, Dave sees ‘evolution’ making the large discontinuous leaps of saltation. He pushes the boat out even further and proposes that the genetic resources needed for those saltational leaps is ‘front loaded’ into the DNA of organisms: that is, organism have ‘potential information’ in the form of front loaded DNA that is not initially realized phenotypically, but is in effect waiting in the wings ready to be called on, perhaps by environmental conditions. This 'potential DNA' might also be a means of explaining the clad structure of species: the genetic information would be sourced in a single ‘front loaded’ genome located in one organism, which then successively bifurcates into a variety of species each species taking some fraction of the potential DNA. According to Dave the information for major biological innovation, instead of being injected bit by bit from random mutations (something which ID theorists believe to be impossible), is already present in the genome, perhaps in the form of apparent 'Junk DNA'. Dave says that “saltation implies front loading” although I think he actually meant to say that front loading is just one mechanism of saltation.

I hope I have done justice to Dave’s position. Dave’s front loading model could be proposed as a working hypothesis and then used, regardless of one’s views about any background intelligence that might be responsible for the front loading, to see how well the model fits the data. Dave, I’m sure, believes his model is a good fit and presumably he sees it engaging the same facts about the fossil record that Gould attempted to engage with his punctuated equilibria.

However, in the comments section of Dave’s post someone points out that front loading isn’t the only way an Intelligent Designer can act in order to bring about saltation: for it is possible that a designer could tinker with the genome from time to time and release the products of these tinkerings into the environment in the form of new species. Herein lies rub for ID. The seemingly arbitrary ways in which such tinkering could take place has the potential to disrupt the rules by which a clade structure could be generated over time. I’m not the first to point out that the choices open to super sentience seem too vast for us to make ID the basis of a rule driven evolution. True, Dave suggests one way in which the Intelligent Designer might consistently work in order to produce the nested taxonomy of clades, but then along comes someone else with another suggestion showing that intelligence has no necessity to conform to this explanation of taxonomy. Yet another of Dave's commentators suggests that common descent, which is thought to be the cause of clades, may not be real but rather evidence of "common design". Hence the whys and wherefores of the clade taxonomy of biology remain a controversial mystery in ID theory.

At this stage I wouldn’t want to emphatically declare that ID is wrong; Let me just say that if ID is right then ID researchers have their work cut out finding any rules or principles that might restrict the options open to an ontology of creative intelligence and this has a series impact on ID's ability to explain the history of life. The open endedness of the ontology with which ID researchers are working makes moving toward a science of evolution difficult if not impossible and ID natural history is likely to remain narrative intense.

For a ‘hard cop’ response to DaveScot see here

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