If quantum tunneling affects evolution then it is a driving factor. Maybe driving isn’t the best word, but it is accurate if changes are observed because of QM.
Quantum tunneling affects all of nature, so evolution would be no different than any other natural process.
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Wrong. It is nothing like your example of fuel and an engine. Natural selection is simply a filter. If you imagine circumstances with no natural selection it just means that none of the variations die out. You could still get drift by replacing natural selection with another mechanism which simply separates out those with similar characteristics from the rest of the population. You can conceivably do without natural selection, but nothing happens without variation.
In fact… this is exactly what we do with breeding… making our own selection of those with the characteristics we like. But the point is that we can do without natural selection. Even without any selection at all, it would be slow but eventually all the same things could be produced.
Variations would die out, fluctuate at intermediate frequences, or reach fixation randomly if there was no natural selection.
What we actually see is some variations becoming more common due to the phenotypic effects. That is adaptation. You can’t explain adaptation without natural selection and variation.
It sounds like breeding wouldn’t work without selection.
I don’t see how. If we compare exons and introns within a gene we see big differences in sequence conservation due to differing levels of selection within each section of DNA sequence. I don’t see how you could get higher levels of sequence conservation in exons compared to introns without selection.
Yes, I agree with your overview of Dawkin’s book here. When I read it, it was more focused on explaining the apparent paradox of kin selection and not anything about information content of in DNA vs. RNA or pre-biotic evolution that @mitchellmckain is mentioning.
‘It’s wild how miserable we are’. Indeed. I know how black my heart can be. God have mercy.
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I think this points up the utility of thinking in terms of multiple levels of selection sometimes operating at the same time, potentially in different directions. What’s good for a gene may be bad for the organism, and what’s good for the organism may be bad for the group or the species.
No, the same things could not be produced without selection. Selection makes adaptive evolution possible; without it, the vastly larger number of maladaptive changes would occur and everything would become extinct. If you kept purifying selection but eliminated positive selection, then no complex adaptive trait would evolve since they’re too unlikely.
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That no variations die out is the very definition of no natural selection. It would would require very unreal condition like infinite space and unlimited resources.
Agreed. That much is true. Adaptation implies a filter.
No. There is no survival of the fittest involved. Yes we choose the traits we like in choosing which to breed. But there is no elimination of varieties unless we want those varieties eliminated (or if we go to any measure to keep them alive) – we can choose such a thing, so natural selection is not a requirement.
Without natural selection there is no adaptation. And so if we are talking about a change in a species from one thing eliminated to another which survives then obviously we don’t have that without natural selection. But variation alone with unlimited resources we we will still see the variations we have today even if they are very rare rather than the norm.
Yes we would see the same things produced. But of course the populations would be very different.
But with an unlimited population you will see even the most unlikely variations. Sure it is not realistic and purely philosophical.
No, that is quite incorrect. In the absence of natural selection, random transmission of alleles in a finite population size guarantees that some alleles will fail to be transmitted. Even with natural selection, the vast majority of new variants are lost because of genetic drift, not selection.
In this universe you will not see them. That’s what ‘they can’t be produced’ means.
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That was my reaction. My second thought was that there are some sci-fi stories I’ve read where there were societies which had managed to protect all their members from radiation and other mutagens, and I thought, too bad, you lose.
In reality, radiation and other mutagens are fairly small contributors to mutation.
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But there is selection which is what I was referring to.
As noted by @glipsnort, without selection all species would go extinct due to the buildup of deleterious mutations. IOW, you wouldn’t see life. It would be gone.
If they are different then they are not the same.
You can’t have the consistent elimination of deleterious mutations and an increase in beneficial mutations without selection. You need selection in order to see this. Variation alone will not do it.
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When selection is our choice then it includes the choice to select everything. This is a stretch of selection to no selection at all.
That is simply an argument that natural selection is unavoidable which is not the same as saying that natural selection is necessary for evolution. If by some magic there were no selection then variation alone can still produce all variations we have today even if they are extremely rare. Natural selection does not actually produce those without deleterious mutations – they are produced by variation. Natural selection ONLY filters out those with the deleterious mutations and thus the same things would be produced even without natural selection.
Different populations yes. Doesn’t change the fact that it is variation which produces the individual organisms. And thus philosophically it is variation which drives evolution and not natural selection. Of course, I grant you that in reality with limited resources, natural selection is unavoidable. But unavoidable is not logical necessity. Without variation there is no evolution. Variation is a logical necessity. Without natural selection there is still a kind of evolution even if it is very different that what we have seen.
Variation is what produces and natural selection is JUST a filter. But I suppose if you define evolution as the alteration of populations and species then you make natural selection a necessity by definition. It is always possible to make something a necessity by definition, like the ontological argument for the existence of God.
Which does NOT mean that most are produced by quantum tunneling. I suspect that except for viruses most are produced by evolved mechanisms for introducing variation into the genome (including that mechanism found in E-coli bacteria where damage from radiation is protected from its own DNA repair system).
What exactly are you trying to get at?
Selection happens. It is unavoidable. The genomes and species we see today are the product of evolutionary mechanisms of which selection is an unavoidable part. Natural selection is a part of reality. So what are you arguing against?
That’s not the universe we live in.
If we had a nearly infinite number of planets with trillions of organisms each that were reproducing for trillions of years it is possible that there might be a handful of organisms that have something approximating the number of adaptations seen in one individual organism on Earth. I can’t seem to understand why you think this point is so important since it doesn’t come close to approximating reality.
The theory of evolution is supposed to explain how the species we see in nature came about. It isn’t about us making natural selection a necessary part of the theory by definition. It is about the mountains of evidence for natural selection acting on species in nature.
Mutations in the genes coding for proteins that copy and repair DNA can certainly alter mutation rates. I wouldn’t say that there are genes whose specific function is to cause mutations. Rather, DNA replication and DNA repair have certain rates of fidelity when copying DNA. In the case of DNA repair, the damage to DNA is already done before those mechanisms kick into gear.
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I suspect that this was not known in the later 1950s when the story was written.
The point of this was always to explain my claim that it is variation rather than natural selection which drives evolution. It was certainly not to argue that natural selection is unimportant. What difference does it make? Orthodox Darwinists with their mantra of “survival of the fittest” can be a little too obsessed with this aspect of evolutionary theory and not realize how big an impact a new source of variation can have.
For example, they have often thought that the habit of protecting the weaker members of the species was harmful to the evolutionary process and have thought that this habit of human beings would be an obstacle to our own evolution. I, however, think the opposite is the case. Our protection of the weaker members of our species acts like a new source of variation (all members of the species do not have to be Daniel Boon’s focused on the art of survival), which stimulates the evolution of specialization. I believe this is exactly what happened in the evolution of multicellular organisms.
Neither mechanism drives evolution alone. They work in combination.
“Orthodox Darwinists”???
Differential reproductive success and neutral drift have been part of the theory for a long time now. “Survival of the fittest” isn’t a mantra. It is at best a mantra in the secondary press.
Who is “they”???
Nowhere in the theory does it say anything about what humans should do. Moral and ethical considerations are completely outside of the theory.
Addtionally, what is “stimulates the evolution of specializiation”??? How does this phrase relate to selection and adaptation?
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(my suggestion to google this didn’t prove helpful when I tried this myself)
This distinguishes the original theory of Darwin from modern evolutionary theory… and particularly the way it has been used philosophically outside of the work of science.
The use of the word “mantra” is to describe the behavior of ideologues. Obviously I would never think this is a description which applies to the proper work of science. I routinely defend science and routinely equate evolutionary theory with the science of theoretical biology. But the fact is that ideas in science frequently have had an impact on human society including the rhetoric of ideologues. And one of the more negative such impacts of evolutionary science are the ideologues of social Darwinism. Researching the origin and use of the phrase “survival of the fittest” is an interesting part of this history.
While social Darwinism was discredited, the notion that protecting the weaker members of the species was contrary to evolution was not something I heard countered by anyone. Books and films still seem to have accepted this notion and thus I saw good reason to find my own counter to it. You do not stop or even slow evolution by protecting weaker members of the species because evolution is driven by variation not natural selection. The fact that you cannot in reality completely have no natural selection, doesn’t change this.
I know of no one who calls themselves an Orthodox Darwinist.
I thought we were talking about the actual science, not ideologies.
In the actual science, neither variation nor natural selection acts alone in the evolution of species. They work in combination.
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Just to clarify, variation is the raw material of evolution and selection is a mechanism used to filter the raw material. I guess that was what you have been saying but condensing the sentences may make this unclear.
Natural selection (“survival of the fittest”) is perhaps the mechanism that is most often mentioned in discussions but it is not the only one. Sexual selection is often important as well as the neutral drift you mentioned earlier.
If we assume that God is somehow guiding the process of evolution towards a goal, that could happen by creating suitable environmental conditions (natural selection favors certain phenotypes) or by directly improving the survival of certain individuals or acting against individuals that carry unwanted genes (some sort of selective breeding). This might work most effectively in bottleneck situations where only a small part of the population survives. When very few survive, relatively small ‘random’ events may determine who survives and who dies.
The big question here is how much does God actively intervene to the process of evolution? Some would say ‘never’, others might be favorable towards the idea.