The Science of God by Gerald L. Schroeder

Author:Gerald L. Schroeder [Schroeder, Gerald L.]
Language: eng
Format: epub, mobi
Tags: Christian
ISBN: 1439129584
Publisher: Free Press
Published: 2009-05-31T00:00:00+00:00

CHOOSING A REASONABLE MODEL FOR CONVERGENT EVOLUTION

I want to learn the statistical probability that nature will produce, independently by random mutations, two structures that are externally similar, although they may use different proteins in their construction. The parameters of this development are speculative. Here I choose a plausible though quite forgiving or lenient model as a means of speculating whether the process is within the realm of feasibility.

There will be no fatalities for wrong mutations. Each mutation will provide a 1 percent benefit (any larger benefit will by necessity demand that wrong mutations be fatal). Population size is 100,000 individuals.11 In this model, mutations must be in sequence (e.g., no lens before we have a light-sensitive region). Each beneficial mutation will be permanently stored on the DNA. It is not allowed to mutate away.

The model, in a sense, “bends over backwards” to favor the theory of convergence and the appearance of the convergent organ.

The major uncertainty beyond estimating the number of mutations required to produce the convergent organ is the assumed rate at which the needed mutations occur. These mutations are significant only if they occur in sexually mature reproductive cells, that is, in gametes. A mutation in, for example, an individual’s skin will not be passed on to that individual’s progeny.

If we take data applicable to existing animals, reported mutation rates of gametes range from one mutation in ten matings to one per 100,000 matings.12,13 Of course that mutation might not occur within the thousand bases we are seeking to change. If the entire genome, containing 3 x 109 base pairs in humans, is vying for the one mutation, then there is only approximately one chance in a million that the mutation will occur within the thousand bases of interest here.14

With a population of 100,000 individuals, even assuming the high reported mutation rate of one mutation in ten matings, there will be 5,000 base mutations per generation. If the genome of interest contains 108 base pairs, there will be only one mutation within the 1,000 bases of interest for each 100 generations. If the genome contains 109 base pairs as in humans, 1,000 generations are required on average. And this mutation may not be correct.

In the simplest model, each point of the thousand DNA sites under consideration has one of four base possibilities. Therefore in the thousand sites there are 4 x 1,000, or 4,000 possibilities, and all but one (i.e., 3,999) are incorrect. Again, the probability of success is one minus the probability of failure. The probability of success in the first of the thousand sites is

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