Andy wrote: >With a random process, every outcome is, of course, equally likely. This i= s why >it could be used to explain "irreducible complexity". With a random outcome, every outcome is indeed equally likely, but that doe= sn't imply that certain *specified* outcomes are as likely as unspecified o= nes.=A0=A0An ace-high royal straight flush in spades is as likely (and as u= nlikely) as any other combination of five cards.=A0=A0But if you shuffle th= e deck and deal a hand, it is very unlikely that it will be an ace-high roy= al straight flush in spades. In order for evolution to get started, there must first be self-replicating= systems.=A0=A0They cannot be *perfectly* self-replicating, because that wo= uld make it impossible for change, and therefore evolution, to occur.=A0=A0= But if the replication is very imperfect, there will not be enough stabilit= y to permit characteristics to spread through a population.=A0=A0This, as I= say, must be in place *before* there can be any talk of evolution.=A0=A0It= is incoherent to suppose that such self-replicating systems themselves "ev= olved." So it is reasonable to ask what the *simplest imaginable* such system would= look like, just as we might ask what the simplest imaginable computer prog= ram for editing text might look like.=A0=A0Remember EDLIN, the little text = editor that was bundled with MS-DOS?=A0=A0The executable program was only a= bout 4K in size, if I remember right.=A0=A0And I'm sure it was not the simp= lest possible text editor.=A0=A0You could probably get something to work in= a program half that size, or less.=A0=A0But at some point you'd approach t= he simplest possible editor, such that anything simpler wouldn't function a= s an editor at all. Then we can ask about the likelihood of producing such an editor by concate= nating random strings of machine language instructions.=A0=A0How many "deal= s" would we expect to have to wait?=A0=A0The problem of getting an appropri= ate self-replicating system from random concatenations of prebiotic molecul= es (amino acids, nucleic acides, etc.) is not solved by saying that all con= catenations are equally likely.=A0=A0Furthermore, we have some idea of the = window of time within which this had to have happened.=A0=A0Current observa= tions indicate that fairly complex (i.e., bacteria) living things were alre= ady present 3.8 billion years ago.=A0=A0The planet only cooled sufficiently= to have bodies of liquid water on its surface about 4 billion years ago.= =A0=A0Prior to that it was too hot to sustain any "broth" for the "primal s= oup."=A0=A0So that gives us about 200 million years to get from prebiotic s= oup to bacteria.=A0=A0And bacteria are by no means the simplest imaginable = living things, so that first self-replicator presumably appeared rather ear= lier.=A0=A0We cannot say how much earlier. This is the reasoning that led Fred Hoyle, and John von Neumann, and others= (Lee Spetner's book Not By Chance is a good source) to reject the random o= rigin of life thesis as mathematically too remote to be believable.=A0=A0Ir= onically, even Francis Crick accepts this conclusion, for exactly the same = reasons.=A0=A0This is what drives him to the "directed panspermia" theory o= f life's origin, according to which life had to have been implanted here by= extraterrestrials. Todd Moody [log in to unmask]