The converse is true for me. No bias, no adaptation. I’m puzzled when drift is assigned an adaptive role.
This discussion is pointless unless you define “much better” vs “slightly better”. Does 10-20% of the genome having sequence-dependent function count as “much better” or only “slightly better” than random?
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Of course. It’s discerned post hoc. Please now excuse me from the silly word games.
No, I’m not saying that. It would be dishonest to claim that I said that. Are you concerned that your comment looks dishonest? You should be.
This is false, and indeed it’s so far from the truth that it makes you look bad.
I don’t think you understand most of what you write about here, but even if you did, I can tell that you have no credibility when you talk about what “people” think.
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I would also like to know who it is that thinks you can just change tRNAs at will without any change to fitness…
I would also, also like to know if @PDPrice realized he was suggesting that biologists were claiming tRNA sequences were irrelevant.
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That seems evasive, because your qualifications are irrelevant. You were asked:
My point is that you omitted one of them discussed here, my objection that Sanford and Carter don’t even present the evidence accurately. That’s not a minor point. It is a dead-simple evidentiary matter and doesn’t even get into interpretation.
This is yet another example of thousands disproving the claim that scientists who understand evolutionary biology and creationists are simply interpreting the same evidence differently.
The reality is that creationists simply ignore the vast majority of evidence. Whether Sanford, Carter, and you are deliberately misrepresenting the evidence doesn’t matter.
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Whether or not a genome is “much better than random” depends upon the fraction that is subject to purifying selection. Neutral theory is perfectly compatible with widespread purifying selection. Therefore, a “random” genome is not an expectation of neutral theory.
Edit: “subject” not “subjective”
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You are excused. Just to be clear, I’m completely convinced by evolutionary theory but doubtful about the adaptive role of genetic drift.
Afaik there are many researchers who think selection is significantly relaxed in the current human population, so that many deleterious variants that would have been likely to be removed by selection in prehistory, now have the opportunity to proliferate due to advances in science and technology. Consider the example of a mutation that makes it likely for you to be born a month or even more too early. Such a child would have been very unlikely to survive as little as 200 years ago.
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Guided? No. As @swamidass has requested, please make more of an effort to understand and accurately express others’ positions before attacking them.
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@Mercer is exactlly right. This is an excercise in understanding one another, not litigating the details. I’m already a bit surprised to see a significant disagreement arise between @Joe_Felsenstein and @glipsnort (I think I’m on @glipsnort’s side here). That’s valuable knowledge to me.
Rather than offering arguments and counter arguments, I want to know what the substantive critiques are at this time, and see if @PDPrice can articulate them in a way that demonstrates understanding of these critiques, even though he disagrees with them. He does not need to agree with them to present them, and the rebuttals/defenses of these critiques are largely noise.
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Let’s clear up a few terms. Using the term “changes” for both mutations and fixation causes confusion.
Mutations are random with respect to fitness. There is not a commonly found mechanism that produces specific adaptive mutations in response to specific environmental cues. The process of mutation produces neutral, beneficial, and deleterious effects.
Neutral theory states that mutations which do not affect fitness in a meaningful way will reach fixation by chance. In contrast, positive and negative selection will affect the rate of fixation/removal for beneficial and deleterious mutations, respectively. Since most of the human genome lacks function a vast majority of mutations will be neutral and will reach fixation by chance. However, mutations that affect fitness within the functional 10% of the human genome will be affected by positive or negative selection.
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It’s hard to know what you mean by “guided”. Certainly evolution is subject to the largely stochastic and contingent effects of mutations. In that sense, it is true that it is more or less just “chance” which mutations occur, and what effects they have. But that in and of itself says nothing about what the probabilities of adaptive vs deleterious are(we can play a game of dice, which means we’re playing a game of chance, and the rules can be such that most throw of the dice give points). Something being largely contingent on chance doesn’t mean it can’t physically result in adaptive changes.
And after all, beneficial mutations do occur. And apparently so much so that continued fitness increase is a recurrent observation. And of course, there are innumerable examples known of mutations that increase fitness, and even some which have been observed to literally result in new and adaptive functions.
No, this is a typical misunderstanding of neutral theory. Neutral theory is about molecular evolution, and the typical fitness effects of fixed mutations. Not that selection does not act on “most changes”(both at the molecular and macroscopic levels) in evolution.
I would have to agree that misleading characterizations and simplistic misunderstandings would, unsurprisingly, lead to people rejecting them.
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Though there is selection still in human society, worldwide. Not everyone gets adequate nutrition, clean water, health care.
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Is there any way I can add more emphasis to this? Because that still isn’t enough!
If an organism is adapted to it’s environment, changes are more likely to be bad, and even more likely still the better adapted it is. So of course most mutations with an effect will be bad if you’re starting from an adaptive peak!!!
Why can’t @PDPrice and the Sanfordites get this very simple point?
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Why not because of genetic entropy affecting the complex molecular machinery involved in DNA repair.
You have already admitted that GE crucially depends on YEC. Thus evidence against YEC is also evidence against GE. So you have admitted that you would have to agree with my “admission”.
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As already noted…
The point has been explained to PDP at least six different times. After a while it becomes apparent someone just doesn’t care if reality directly contradicts his claims.
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Could be, but Dr Felsenstein would of course not accept that answer. I am not aware of any place that Sanford has argued for an increasing rate of mutations, but I could definitely see how that would make sense as an outworking of genetic decay. Dr Felsenstein only brought up that concept as an unevidenced rescuing device to avoid the conclusion of GE in the first place. Ironically, though, if correct that would represent a kind of GE in and of itself.
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