Replies

In your example, your numbers indicated that the mutant, and only the mutant, was part of a breeding pair that produced 10 offspring, half of which inherited the mutation, as per my assumption 1 (sexual reproduction). However, your population size as a whole was increasing as if each individual was producing 10 offspring, as per my assumption 2 (asexual reproduction). Either every individual pairs up to produce offspring or every individual produces offspring asexually, in which case all the mutant's offspring are mutants. You cannot mix the two types of reproduction, as you did in your example.

You are correct, I was wrong. Now I understand my mistake. In sexual production we have a pair of organisms and in a stable population there will be two progeny from the organism with the mutant, which according to the laws of chance means that one of the two should carry the mutant gene. So the fate of a new mutation is not as awful as I thought it was.

However, that as you say " A trait which confers neither a survival advantage nor disadvantage remains in the population at a constant frequency" presents severe problems for the theory of evolution. For one thing, such a mutation will never spread through the population. This is necessary for it to be able to gain mutations which will turn it into a favorable mutation and give it the possibility of becoming widely adopted throughout the species.

There is another problem with such a new mutation not being able to spread. Even though it is true that a trait remains in the population at a constant frequency, this is only true when the sample is large. A new mutation has (in a constant size population) only one chance. That is why even such a pro-evolutionist site as TalkOrigins, and a pro-evolutionist author there is forced into the admission that:

Neutral alleles Most neutral alleles are lost soon after they appear. The average time (in generations) until loss of a neutral allele is 2(Ne/N) ln(2N) where N is the effective population size (the number of individuals contributing to the next generation's gene pool) and N is the total population size. Only a small percentage of alleles fix. Fixation is the process of an allele increasing to a frequency at or near one. The probability of a neutral allele fixing in a population is equal to its frequency. For a new mutant in a diploid population, this frequency is 1/2N.
From: Introduction to Evolutionary Biology

This may sound strange to many, but the originator of the theory of population genetics, Ronald A. Fisher in "The Genetical Theory of Natural Selection" (1958), admitted as much in spite of being such a devout evolutionist that he had originally tried to challenge the accuracy of Mendellian genetics. The reason for the loss of such a new gene is quite simply explained. With only one sample, at any time that the laws of chance do not even out, (in this example when neither of the two progeny carries the mutation), the mutation will die out. Since the mutation is not spreading, the likelihood of this happening is quite high. In fact, even a mutation with a slight degree of benefit would also be lost in this manner.