(Via Rand Simberg) David Janes has a really interesting take on the whole Intelligent Design vs. Evolution dustup that’s been spreading its way throughout the blogosphere like some selfish gene (or was it started by He Who Is Reynolds, the Blind Watchmaker of our digitized little blog world…?): “Why evolution is as good a scientific theory as gravity“
Janes deals with the falsifiability of the theory of evolution.
Me, I’m gonna go deal with a hamburger and some curly fries. Who knows, the fact that I’m not being eaten by either a cow or a potato may even prompt me to say a little prayer in that heavenly instant just before I sink my teeth into the meat…
Um, Jeff eats a hamburger…Survival of the fittest? Or “there but for the grace of God go I”….?
BIG problem with his falsification tests– I don’t think that the first is sufficient for falsification, but it has DEFINITELY not been passed. Even restricting ourselves to a small number of species of certain types of fungi (with which I am most familiar), there are MANY plausible phylogenetic trees. Selections of different independent sets of genes DO result in very different phylogenetic trees. In addition, wildly different trees result through either use of parsimony or Bayesian analysis, and as additional gene data is obtained. I’ve seen and done some work in the area.
Of course, this is not a falsification, since it could merely come from incomplete data and insufficient tools– or perhaps it’s just impossible to completely determine the correct answer. One would expect to find a more stable tree between wildly different species. Of course, this is hardly a “proof” of evolution, either, since the phylogenetic trees obtained could simply reflect the broad amount of similarity and differences in the genetic structures of the species.
Finally, of course, the argument does not answer that sophisticated sort of ID argument– the one that purports to accept descent from a common ancestor, but claims that natural selection and the actions of mutation alone are insufficient (esp. in the time lengths considered) to cause the sufficient variations and speciation observed. That argument is a negative one that can only be answered through careful examination and argument. (I’m not sure how well it’s ever been answered– it’s one of the things, like explicit examples of speciation, that is rarely discussed.)
Interesting comments. I am thinking of differing species and mainly thinking of comparisons of the tree near the “leaf” area. I’m not familiar with fungi (I even refuse to eat them, to my wife’s despair), but could it be (as you allude to) that there’s a statistical problem—that maybe the trees “don’t work” with really closely related species. For example, if we made a phylo-tree across humans, I’m not sure if it would reflect anything meaningful at all.