The last piece of rust that interrupts vital function will be selected against and is not effectively neutral. It is deleterious and is selectable. That’s the problem with Sanford’s thesis. You don’t need to be perfect to be a successful species.
Of course. But by then your whole population is mostly rusted out. You can’t select away the whole population. Mutations are only selected for or against individually. You can’t just start over with a new genome. If we could then genetic entropy would not be an issue.
Apparently, being mostly rusted out has worked for 3.5 billion years.
But you can remove deleterious mutations as they arise, especially those that prevent reproduction or are lethal.
Sanford’s explanation for why GE has allowed life to exist on the Earth for over 3.5 billion years is…?
Or maybe that assumption of yours is incorrect. This evidence says it is.
But you can remove deleterious mutations as they arise
Everything I’ve just showed you here says you can’t. Most mutations are too small to be selected out.
It isn’t an assumption. It is a conclusion drawn from mountains of evidence in the field of geology.
Then I would suggest that you go to my thread on pocket mice where this is demonstrated in living populations.
It’s even demonstrated in the H1N1 data where the number of fixed mutations is well below the rate at which mutations occur.
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You’ve shown zero evidence you understand this critical point. What about the concept is so difficult?
The next question we have to ask is the ratio of slightly beneficial to slightly deleterious neutral mutations. These would be effectively neutral mutations, so we wouldn’t be able to detect whether they are slightly deleterious or slightly beneficial using population demographics. So how do we determine what this ratio is? How did Sanford determine this ratio?
If the tiny effects we are talking about have to do with the number of bases in a genome, then a genome with a stable number of bases where deletions are balanced by insertions would have no net change in fitness. This appears to be the case for our branch of the primate tree, with the gibbon, orangutan, gorilla, and human genomes having nearly the same base count over 10’s of millions of years.
If Sanford really wants to make these grand claims, then we need evidence for the distribution of effects caused by effectively neutral mutations, and I have yet to see it.
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There is every reason to believe the ratio would be either the same or worse. Why?
“Even the simplest of living organisms are highly complex. Mutations—indiscriminate
alterations of such complexity—are much more likely to be harmful than beneficial.”
Gerrish, P., et al., Genomic mutation rates that neutralize adaptive evolution and natural selection,
J. R. Soc. Interface, 29 May 2013; DOI: 10.1098/rsif.2013.0329.
The onus would be on you to prove that somehow, against all evidence and logic, the majority of effectively neutral mutations are somehow beneficials. I don’t think any serious scientist thinks that is the case.
Right here at Peaceful Science.
That’s not how science works. I don’t make similar demands of you, and I’m gonna ignore them when directed my way.
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What are those reasons?
In the context of the paper, he is talking about mutations that affect fitness which would exclude effectively neutral mutations.
Sanford needs to support his claim that there are more slightly deleterious effectively neutral mutations than beneficial ones.
All the science shows that mutations (including these effectively neutral ones) are much more likely to be harmful. The above quote was a general statement applying to all mutations, and certainly was not excluding ‘effectively neutral’ ones. I challenge you to find any strong evidence that effectively neutral mutations are mostly beneficial (or even 50/50)
Then please cite the science. Remember, we are talking about effectively neutral mutations, not detrimental mutations that do affect fitness in a detectable manner and can be seen by natural selection.
I disagree. My reading of the paper shows that the author is comparing beneficial and deleterious mutations, not effectively neutral mutations. I don’t see anywhere in the paper where he deals with neutral mutations. The major push of the paper is the balancing act between deleterious mutations, beneficial mutations, and natural selection. Can you find where in the paper the author addresses neutral mutations?
I appreciate your time. It looks like the premise you’ve chosen to dispute is “most effectively neutral mutations are damaging.” @Rumraket I wonder if you’d agree and join him in disputing this?
I know you’ve been asked this, but I must confess to skimming and am repeating a question. How do you explain the viability of rapidly generating organisms like bacteria? Why hasn’t GE forced them into extinction long ago?
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I should hope so, since that premise is without any foundation. Assuming that evolution theory is correct, then in any long-lasting lineage effectively neutral mutations should be balanced between slightly deleterious and slightly beneficial, except in cases where the population size has decreased or increased. In those cases, one or the other will be more common until equilibrium is again restored.
There’s a nice example in humans and similar species. We know one class of slightly deleterious mutations are those that change one codon for another that codes for the same amino acid. Different codons typically have very slightly different fitnesses because of different tRNA abundances and the like. In bacteria, we can clearly see this codon bias operating, meaning that there actual codons tend to be the slightly fitter one (and there are a host of very slightly deleterious mutations waiting to happen). In humans, on the other hand, there is no trace of this effect, and no preference for better codons – because the slightly deleterious mutations occurred long ago in our distant ancestors, so that now there are just as many opportunities for bases to mutate back to the better codon as there are opportunities for slightly deleterious mutations.
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I don’t think the science of population genetics would back up this statement. I have never seen any scientific paper talking about the distribution of fitness effects that would suggest that beneficial and deleterious mutations are split 50/50. It’s completely obvious that that would never be the case. Why?
“Even the simplest of living organisms are highly complex. Mutations—indiscriminate
alterations of such complexity—are much more likely to be harmful than beneficial.”
Gerrish, P., et al., Genomic mutation rates that neutralize adaptive evolution and natural selection,
J. R. Soc. Interface, 29 May 2013; DOI: 10.1098/rsif.2013.0329.
Not true. Humans have done very well for 2 million years without God’s help. From stone tools to landing on the moon to smart phone, mankind has done amazing things. And I am optimistic that mankind will continue to do even more amazing things without the help nor involvement of any God.
The science of population genetics is what I do for a living.
It’s an obvious consequence of selection coefficients that are too small to be acted on by natural selection, and much too small to be measured directly. What kind of paper could you write about it?
That paper does not address the kind of very slightly beneficial and deleterious mutations you’re talking about. Not at all.
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