Replies

A polite response thank you.

I took the post as a "here's what's needed" list.

As I understand it, a gene must duplicate for there to be successful evolution because the existing beneficial traits must remain for the organism to be competitive in selection. I guess this would be a neutral mutation.

This duplicate gene must then survive -- which GK3 says is unlikley, a position, which I think, is not without logic.

The duplicate then must mutate again into a new beneficial trait.

Again, that's as I how I understand it.

The first question is has this been observed in sexually reproducing multi-celled creatures -- not just the genetic duplication, but the inheritance of the new gene and it's subsequent beneficial mutation?

The second question would be could this phenomena be expected at a rate to explain Earth's biodiversity given 3.8 billion years?

As I understand it, a gene must duplicate for there to be successful evolution

Nope. That's just an avenue that prevents a loss of information because the original gene is retained. Mutations happen all the time without prior duplication.

This duplicate gene must then survive -- which GK3 says is unlikley, a position, which I think, is not without logic.

It is without logic. A gene must always go with one gamete or another and has a 50% chance to be inherited by each child. Consider a man having a specific mutation 10 generations ago. If his descendents were prolific and he has 500 descendents now, ~250 will have the mutation (check family trees, 500 descendents is quite possible including in my family).

The duplicate then must mutate again into a new beneficial trait.

Or a survival-neutral one - it may only be beneficial in much different, or stressful, circumstances. Hundreds of traits have been traced in humans that provide no obvious enhancement to survival. Each side my own family tree contains several obvious (both sex-linked and non-) genetic mutations that each new generation gets to investigate when they discover them.

See above, numerous simple genetic traits in humans are tracable. Significantly beneficial or detrimental mutations are investigated even more closely. Some have been traced back to the original individual mutant. I'm surprised you even questioned this idea.

The second question would be could this phenomena be expected at a rate to explain Earth's biodiversity given 3.8 billion years?

That requires additional information about the past genetic material, the viral environment, and past rates of mutation.

This duplicate gene must then survive -- which GK3 says is unlikley, a position, which I think, is not without logic.

It is unlikely that this gene "survives" if it is harmful but if it is neutral the chance that it is spread in a population over time is not that low.

The duplicate then must mutate again into a new beneficial trait.

Exactly.

I'm sure it has been observed but I don't have any examples right at hand now but I think a websearch should turn up some examples.
Of course, once a gene is in the genome it will be inherited except if a new mutation occurs that deletes this particular gene (but this is really rare).

The second question would be could this phenomena be expected at a rate to explain Earth's biodiversity given 3.8 billion years?

Why not? You have to keep in mind that this is a parallel and not a serial process.
Additionally asexually reproducing organisms have very short reproduction cycles. Sexually reproducing organisms may not have such short reproduction cycles but they can better accumulate beneficial mutations because they exchange genetic material.

This duplicate gene must then survive -- which GK3 says is unlikley, a position, which I think, is not without logic.

You've been around on these threads for months now at least. I wonder how you can not miss that there's no position of g3k's that hasn't been rebutted over and over and over and over. (Not necessarily by the same people, however, as at any given time some people are giving up trying to get through to him and some unsuspecting newbies are just stating.)

There seems to be some positive pressure to retain (and rapidly modify) ostensibly neutral duplication mutations.

To find out how the duplicate evolved, the researchers created nine designer mutant proteins, each with one of the nine amino acid changes that separate the duplicate from the original. Every change reduced the enzyme's ability to degrade double-stranded RNA--the enzyme's original job. This hints at a lack of negative selection. But statistical analysis showed that the duplicate gene evolved much faster than would be expected from random change, suggesting that positive selection was at work too, the team reports in the March 2002 issue of Nature Genetics.

That could possibly be because having a few working experiments going on at any given time increases a species's flexibility in the event the selection pressures change. Or maybe there was some other hidden functionality in that langur case.

Computer modeling so far says that purely neutral mutations do have a tendency to slowly die out over time, but then there are always new ones happening. Thus, at any given time, there tends to be more than one version of, say, hemoglobin floating around in a species.

The point was made that to account for some evolutionary changes in hemoglobin, one requires about 120 amino acid substitutions...as individual events, as though it is necessary to get one of them done and spread throughout the whole population before you could start processing the next one...[and] if you add up the time for all those sequential steps, it amounts to quite a long time. But the point the biologists want to make is that that isn't really what is going on at all. We don't need 120 changes one after the other. We know perfectly well of 12 changes which exist in the human population at the present time. There are probably many more which we haven't detected, because they have such slight physiological effects...[so] there [may be] 20 different amino acid sequences in human hemoglobins in the world population at present, all being processed simultaneously...Calculations about the length of time of evolutionary steps have to take into account the fact that we are dealing with gene pools, with a great deal of genetic variability, present simultaneously. To deal with them as sequential steps is going to give you estimates that are wildly out." (pp. 95-6)

Silliness at the Wistar Symposia, 1966.

Gore is basically using the Haldane's Dilemma argument, that there's not enough time to accumulate mutations before they die out. Medved and now PetiteMericco like to quote Walter ("Biotic Message" Remine) doing the same. It's bogus, as analyzed in painful detail here.