Re: Comments on Snoke's approach

From: Randy Isaac <randyisaac@adelphia.net>
Date: Fri Sep 23 2005 - 20:15:14 EDT

Cornelius, I was hoping you'd go for the bait and give me a chance to explain further. This is an argument from physics and physicists have to grossly oversimplify the world in order to deal with it. So we need to keep it very very simple. First we need two assumptions:
1) There exists an organism(s) at some point in time which reproduces at some rate. (could be a single cell or multi-cell organism)
2) The DNA within the organism has a very small but non-zero error rate of replication.

The first assumption is pretty obvious from observation. Organisms exist today and there is evidence they existed in the past. The second is also observed but it is something we would expect on thermodynamic grounds since it is energetically too costly to have error-free reproduction.

From these assumptions, the second law of thermodynamics tells us that after a time much longer than the reproduction rate, the population of organisms will display all possible variations of the DNA. It's a simple result of the tendency for all systems to increase in entropy. For these systems, that means all viable variations of DNA. Since we observe that individuals and species are differentiated by variations of DNA, it follows that the world will develop a vast diverse range of species.

It is left to chemists and biologists to figure out the gory details! How long a period of time? How many species? Which ones? Details, details, details. The main vulnerability is whether conditions might change to the point where no organism can reproduce. That would of course halt the process. There seems to be no fundamental reason why organisms have to be able to exist so the conditions necessary for life might not occur at some point in time. But for the last few billion years, it seems that conditions have been peculiarly favorable on this planet. So if we could only figure out how the first organism(s) got going, there's at least no fundamental reason why a large number of species couldn't eventually evolve. Figuring out how and why and when is the fun that biologists are having these days.

Randy
  ----- Original Message -----
  From: Cornelius Hunter
  To: asa@calvin.edu
  Sent: Thursday, September 22, 2005 11:22 PM
  Subject: Re: Comments on Snoke's approach

    You also said that "One could argue effectively that once there exists a reproducing organism, the probability that in time there would be a vast diverse range of species is close to unity." Again, I don't know how one could defend this. Everything we understand about population genetics and adaptation points to limits to adaptation. And there is no effective argument for how the intricate complexities in biology could have arisen from a single cell. All we have are broad speculations based on the presupposition that evolution has occurred.

  --Cornelius
Received on Fri, 23 Sep 2005 20:15:14 -0400

This archive was generated by hypermail 2.1.8 : Fri Sep 23 2005 - 20:18:26 EDT