Several "experts" posted comments the other day (on the 'genetic death' thread) indicating that they lack a basic comprehension of what the theory of evolution is. Several also claimed that mutations were not involved in evolutionary theory and that only substitution of existing alleles were.
I mean, you can't really have much of a discussion on something when the adherents of a theory don't even understand it properly.
It is sufficiently obvious that you cannot get new kinds of animals by substituting existing alleles. If nothing else, human breeding of dogs and other animals demonstrates that. Human dog breeding involves selection beyond anything which would ever occur in nature and all it ever produces is dogs...
Walter Remine preceeds his discussion of the time scales involved in evolutionary development with the following discussion of the standard modern evolutionary synthesis, which is the generally agreed upon notion of what the theory of evolution involves:
Quote:
These substituted traits are simple changes having arisen by mutation, these can be of many types. The new trait might be a DNA inversion, gene duplication, or deletion, for example. Also, organisms are not merely the possession of the right genes. The position and sequence of genes on a chromosome are important to their action, expression, and propagation. So, a substituted trait can be something as simple as a new location of a gene on a chromosome. The substituted traits can be many different things. Yet, every time you wish to move a gene to a new position, or delete a gene, or duplicate a gene, or substitute any trait,4 no matter how trivial, then there is a cost to be paid.
According to the neo-Darwinian synthesis, these substituted traits are typically a new version of a gene - an allele. The new substituted gene typically differs from the old gene by one newly mutated nucleotide. So, the substituted trait is nominally a nucleotide.
That's the basic idea of the theory of evolution. Note that replacing genes with new versions of the same genes is not the same as substituting existing alleles around.
The basic idea according to all realistic accounts is that "beneficial mutations" pile up until you have macroevolution and new kinds of animals.
Again, the vast bulk of all mutations are harmful or fatal, or at best neutral with no possibility of leading to the development of new kinds of animals, so that it is not possible to picture new kinds of animals forming up by the simultaneous spread and fixation of beneficial mutations; the harmful mutations would swamp the process and it would die out before it evolved into anything new and better.
What happens (according to the theory) is that one beneficial mutation becomes fixed in the population, and then another and another and another.
The theory also requires that the old stock die out as each new beneficial mutation becomes fixed, due to selective pressure. That is the "genetic death meatgrinder" I mentioned.
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