Design, evolution and many worlds

The following image graphs the outcome of a simulation of a random process where a particle starts in the middle of the big square and moves by small steps in random directions until it reaches an edge.

It sure looks from the picture like there was a bias in the particle in favor of movement to the right, and that the particle was avoiding the black lines (you can see at a few points where it seems to be approaching the black lines and then jumps back) and searching for the red edge on the right.  If you saw the particle behaving in this way, you might even think that the particle has some rudimentary intelligence or is being guided.  To increase the impression of this, one could imagine this particle doing something like this through a complex labyrinth.

But in fact the picture shows a run that doesn't involve any such bias or intelligence or guidance.  However, it took 23774 runs until I got the one in the picture!  What I did is I had the computer repeatedly simulate random runs of a particle, throwing out any where where the particle hit the black boundary lines before it hit the red edge.  In other words, there is a bias at work  However, it is not a bias in the step-by-step movements of the particle, but a selection bias--to get the picture above, I had to discard 23773 pictures like this:

Sampling multiple cases with a selection bias can produce the illusion of design.  Most cases look like the second diagram, but if I only get to observe cases that meet the criteria of hitting the red edge before hitting any black edge, I get something that looks designed to meet the criteria (it looks like the process is run by biased chances, whereas the bias comes from conditioning on the criteria).

Now, suppose that evolutionary processes occur at a large number of sites--maybe a very large number of planets in a single large universe or maybe in a large number of universes.  Suppose, further, that intelligence is unlikely to evolve at any particle evolutionary site.  Maybe most sites only produce have unicellular critters or vast blankets of vegetation.  But a few produce intelligence.  We then will have a sampling bias in favor of the processes happening at sites where intelligence results.  And at such sites, the evolutionary processes will look like they have a forward-looking bias in favor of the production of intelligence, just as in my first diagram it looks like there is a bias in favor of getting to the red line and avoiding the black lines (think of the diagram as phase space, with the black lines marking where total extinction occurs and the red line marking where there is intelligent life).  

This means that we will have the appearance of design aimed at intelligence.  This forces a caution for both intelligent design theorists and evolutionary theorists if there is reason to think there is a large number of sites with life.  

The intelligent design theorists need to be very cautious about taking apparent end-directedness in the phylogenetic history that led to human beings to be evidence for design.  For given a large number of life sites and the anthropic principle, we expect to see apparent directedness at the production of intelligence in the process, just as in my first picture there is apparent red-directedness and black-avoidance.  This means that intelligent design theorists would do well to focus on apparent design in lineages that do not lead to us, since such design is not going to suffer from the same anthropic selection bias.  The cool stuff that spiders do is better fodder for intelligent design arguments than the mammalian eye, because the mammalian eye "benefited" from anthropic selection.  However, this also weakens the design arguments.  For design (pace some prominent intelligent design theorists) involves offering an explanation of a phenomenon in terms of the reasons a plausible candidate for a designer would likely be responsive to.  If the phenomenon is one that promotes the development of intelligent life, the design explanation could be quite good, for there are excellent reasons for a designer to produce intelligent life--intelligent life is objectively valuable.  But if the phenomenon is a spider's catching of flies, the reasons imputed to the designer become less compelling, and hence the design explanation becomes weakened.  

On the other hand, evolutionary theorists need to be careful in making precise generalizations about things like rates of beneficial mutations that apply equally to our ancestors and to the ancestors that other organisms have not in common with us.  For given a large number of sites where life develops, we would expect differences in such things due to the anthropic sampling bias.

This also suggests that we actually could in principle have evidence that decides between the hypotheses: (a) intelligent design, (b) naturalistic evolution at a small number of sites and (c) naturalistic evolution at a large number of sites.  

Suppose we find that the rate of favorable mutations among our ancestors was significantly higher than  the rate of favorable mutations not among our ancestors.  This offers support for (c), and maybe to a lesser degree for (a), but certainly against (b).  But suppose we find equality in the rates of favorable mutations among our ancestors and among our non-ancestors.  Then that offers evidence against (c) and depending on whether the rates are as we would expect on evolutionary grounds, it is evidence for (b) or for (a).  

I am assuming here that the number of sites is finite or there is some way of handling the issues with probabilities in infinite cases.