On Aug 29, 2005, at 4:45 PM, Roy Plotnick wrote:
I've been mulling over potential arguments against ID from a biomechanics viewpoint. I've seen a number of mentions of the idea that the "knee is badly designed, the back is badly designed, the retina is inside-out etc..." What I have not seen discussed in this context, however, is the fundamental postulate of ID; i.e., that some biological systems are so complex that removal of even one part leads to failure - i.e.., "irreducible complexity." What I am thinking is that even if true, it would actually be an argument against an "intelligent designer," i.e., a competent engineer would design systems against such a situation, such as building in redundancies wherever possible (the multiple fuel sensors on the space shuttle come to mind). I've discussed this with Steve Vogel at Duke and he puts it (with his typical eloquence) like this "Maybe minimal use of redundancy, a terrifically effective way to reduce the change of disabling failure, in nature, is evidence against intelligent design. After all, if something is 99% reliable and backed up with something else that's 99% reliable, you have gone from a chance in a hundred of trouble to a chance in ten thousand. Two things don't halve the worry, they reduce it a hundred-fold!" Offhand, the only redundant systems I can think of is being able to breath through your nose and mouth and that some systems (e.g., kidneys) are paired.
My question to all of you is if anyone else has made an argument along this line. If they haven't I'm going to pursue it further. -Roy
A few brain-dumps:
Redundancy is a complex phenomenon that comes in various types (at least 4). Most important is that it, like everything else, can evolve. Hence, both non-redundant and redundant systems can change their status through time. Elimination of redundancy is one way that complex structures appear; but redundancy can also re-appear and release functionally constrained components of a system.
For some examples, see:
Thornhill, R. H. & Ussery, D. W. (2000). A classification of possible routes of Darwinian evolution. Journal of Theoretical Biology 203, 111-116.
(a very helpful reference, even if one might not completely go along with its bioengineering approach)
and
(less modestly)
Budd, G. E. (1998). Arthropod body plan evolution in the Cambrian, with an example from anomalocaridid muscle. Lethaia 31, 197-210.
and
Stone, J. R. & Telford, M. (1999). Using critical path method to analyse the radiation of rudist bivalves. Palaeontology 42, 231-242.
and
Rowe, T. (1996). Coevolution of the mammalian middle ear and neocortex. Science 273, 651-654.
and
Galis, F. (2001). Key innovations and radiations. In The character concept in evolution (ed. G. P. Wagner), pp. 581-605. Academic Press.
and
Force, A., Lynch, M., Pickett. F. B.. Amores, A., Yan, Y. L. & Postlethwait, J. (1999). Preservation of duplicate genes by complementary, degenerative mutations. Genetics 151, 1531-1545.
and so on.
I am currently revising a fairly monstrous paper on this topic, which I hope will be completed fairly soon...
Reading Riedl's eclectic classic Riedl, R. (1978). Order in Living Organisms: A Systems Analysis of Evolution. John Wiley & Sons would also be highly amusing and insightful!
All best
Graham