Thursday, July 07, 2005

Turtles all the way down

Turtles all the way down.

Around the net I’ve seen this expression come up called ‘turtles all the way down’, usually referenced to intelligent design. The term comes from a story, of unknown source as it seems to come up often from different people, where essentially a famous lecturer was giving a talk on astronomy. After he was finished a little old lady came down and told him he had it all wrong.

“The world is really on the back of a giant tortoise” the woman said to which the scientist asked, in an attempt to stump her most likely, “Well then, what is the tortoise standing on?” To this the lady triumphantly replied “You’re very clever young man, but it’s of no use – it’s turtles all the way down”.

In many respects this is the problem that intelligent design faces when it proposes a ‘designer’ is natural. For example, when we take Dembski mathematics, fancy as they are and apply it to the designer we find, unsurprisingly, that the designer must himself be designed. If we do the same thing again, we find that each designer in turn requires another designer. Eventually, we have an infinite regress of designers, each one designing the previous one; turtles all the way down in other words.

The solution to this problem from ID, but the one they refuse to admit, is that inevitably they must admit somewhere down the line that there is a supernatural designer. Essentially a designer that according to their own ideas doesn’t require being designed first by something else and can do the ‘initial’ designer. Now this doesn’t invalidate immediately that we may have been designed as some assert. We could be the product of design from an alien race that was really created by a supernatural entity to begin with for whatever purpose- it is just that we have a perfectly good explanation in evolution already.

Unfortunately, when we meet that race and share tea we suddenly end up at square one anyway: What designed our designers? It’s not surprising to me that those who want to masquerade ID as some form of ‘valid’ science suddenly become completely allergic to this concept and try to explain it away as fast as possible. Essentially, they want to have their pet concept that things were ‘designed’ yet they don’t want to deal with explaining how it was designed.

For example, let us just say that there is some biological structure we want to know is designed. As scientists, natural questions arise such as how did the designer produce the structure in question, what method did the designer use and why did the designer make the particular structure in that matter. More importantly, they need to make a hypothesis that competes with the evolutionary hypothesis and provides a better explanation not just a explanation. The explanation of a designer must account for the methods, reasons and motivations for making that structure to be conclusive.

For example, let’s say there is a new terrible disease that has struck the world and is beginning to kill hundreds of people world wide. How could we tell if this is an organism that has evolved by chance or that it has been designed by terrorists wanting to use it as a biological weapon (say it escaped). We would have two competing hypotheses immediately for the origin of this disease, but not because of the ideas of the ‘intelligent design’ movement, but rather because of something we do know:

We know about human designers.

Firstly, I would try to isolate the organism that is responsible, most likely a virus of some sort and then isolate its DNA to sequence it. Once sequenced, in other words we have the ‘code’ of nucleotides (Adenine, thymine, cytosine and guanine) that make up this organisms DNA. We could infer it to be designed by humans or that it evolved by looking at this organisms genome.

In the case of a human designer, we could look at the series of genes and how they are linked together in the organisms DNA. Commonly used in the laboratory are enzymes called ‘restriction enzymes’ that cut DNA at specific locations. Importantly in genetic engineering, they leave little overhangs of the DNA strand they cut allowing you to ‘stitch’ the DNA fragments they produce together. This is important in making transgenic animals and producing novel gene clusters (for example to insert a gene into an expression system like a plasmid).

If we saw a series of genes along the organisms genome that look to have restriction enzymes placed exactly between each one, that would almost be ‘smoking’ gun evidence that this may have been an organism designed by human beings. If we look further and we find genes that would have been difficult, if not impossible to have been captured through horizontal gene transfer, such as entire genes of the human immune system like IL-4 (which when inserted into mousepox virus made it much more lethal) then that would be even better evidence for this organism being designed.

On the other hand, this hypothesis still has to compete with the current scientific understanding of evolution. We already know that viruses can exchange segments of DNA if they co-infect the same cell as another virus, and that bacteriophages can capture pieces of DNA from bacteria and transfer them to other species. Additionally, retroviruses can insert themselves into the genomes of their host, being a potential explanation for the origin of a human gene.

But again, I want to emphasise something we’re talking about an organism being detected by design yes, but because we know of the methods of the potential designer. As ID proponents often point out while they sneeze half to death, ID isn’t about trying to work out what the designer is or the methods that it used, just that somehow life is designed.

But let’s review that more carefully:

1) Life is designed

2) The mechanism of this design is not something we want to talk about

3) Ergo, if we don’t want to talk about a mechanism then by default we are admitting we can’t talk about the designer

4) With no mechanism or designer, how do you infer design at all to begin with?

Let’s go back over my potential bioweapon example

1) A new organism is discovered and it may have been a designed weapon

2) We know 1 could be possible, because human beings have the ability to manipulate the genetics of living organisms, using restriction enzymes, plasmids we’ve ‘domesticated’ and other techniques.

3) We know that humans would have the motivations to make such a deadly organism because biological weapons have been used in the past.

4) As we know 2 and we know 3, we can directly test 1 to establish if it was designed or not because we have suitable grounds to determine this by the methodology and knowledge of a potential designer (human beings).

Additionally, unlike claims of ‘design’ from most ID members, this is also inherently falsifiable logic because we can rule that another mechanism (evolution) may be a much better explanation. In fact, it may be it was simply an example of a newly evolved pathogen but it would at least in both cases be testable as to the origin of the newly derived organism.

Inherently ID has the problem where it is incapable and indeed unwilling to talk about their ‘designer’. They know, just as well as their opponent’s, that ultimately ID rests on no true empirical or testable ground without having an actual verified designer. There is no way for them to ever rule out evolution, which itself, has numerous testable and falsifiable claims about the organisms and structures we see. Without a way of providing the mechanism of design or the designer, they provide no logical reason to infer any sort of design in human beings or anything else for that matter.

ID is, without a designer and refusing to talk about anything to do with said designer isn’t “God-of-the-gaps”. ID is “No-designer-at-all-to-put-into-the-gaps” which is even worse, because at least with “God-of-the-gaps” you at least have named the designer. Even when you have you then end up at square one if that designer was natural, who designed them? Then it's back to turtles all the way down.