On 10/01/2011 06:22 PM, Darren New wrote:
> Invisible wrote:
>> You seriously expect me to believe
>
> That's a terrible argument. "I couldn't imagine how something as complex
> as predicting the future that way could have happened" is just as bad an
> argument as "I couldn't imagine how hemoglobin came about."

OK, well how about chaos theory? That puts hard bounds on what can and 
cannot be predicted. I should imagine that over the course of 4 billion 
years, one single stray photon would probably be enough to perturb the 
system sufficiently that it wildly diverges from your predictions. So 
you'd have to predict solar activity too. (Not to mention random stray 
comets colliding with Earth.)

On top of that, the effect of living organisms themselves is 
significant. So in order to work out what what types of organisms you 
need to design, you need to know what environments will be available, 
which *depends on* what types of organisms you design.

Seriously, you don't need to be a chaos theory expert to see that all of 
this is wildly impossible. (Not forgetting that the original premis is 
already impossible because the number of species wildly exceeds the 
information content of the first genomes.)



Now, Behe put forth the idea of "irreducible complexity". The idea being 
that a system is irreducibly complex if removing any single component of 
it breaks the system. Such systems, Behe asserted, cannot evolve.

Of course, that's a bit like buying a car, removing the engine 
management system, observing that the car no longer works, and arguing 
that the car cannot have been invented before computer technology became 
available. Which, obviously, is absurd.

Then again, that's not *quite* the same, since the designs of artificial 
devices can make sudden jumps. Evolution, in general, can't do that.

Dawkins showed that irreducibly complex systems can in fact evolve. For 
example, suppose protein A exists, and does something useful. Now 
suppose that a protein B comes along, which makes protein A slightly 
more efficient. Assuming whatever A does is beneficial, doing it better 
is obviously something that natural selection would favour.

What happens next is that A and B co-evolve. Any change in B which 
enhances its effect on A would tend to be favoured. Any change in A 
which enhances the effect of B on it would also tend to be favoured. 
Fast-forward a few million generations and I wouldn't be at all 
surprised if we now have a situation where A doesn't even *work* any 
more without B.

In other words, the system has become irreducibly complex. And of 
course, there's no particular reason why a protein C can't join the 
party at some point along the smooth continuous route to irreducible 
complexity. And then we would have 3 interrelated proteins that only 
function in combination with each other.

Behe also chose an unfortunate example of an irreducibly complex system: 
a cellular motor. He pointed out that it's a complex of 9 proteins, and 
removing any one of them breaks the motor, so therefore it could not 
have evolved. Except that somebody recently discovered a parasite that 
uses just 2 of these proteins to make holes in the cell walls of its 
host. So those 2 proteins on their own do something useful. They don't 
make a motor, but they /are/ useful (for something slightly different).

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