Hey, a post I can understand!
@T_aquaticus wrote ID arguments are meant to stop science and I replied how something from nothing would also be an end to science
Do you see the connection?
It was a wonderful providence having Plantinga’s great student at an unremarkable university in South Florida. The following year he moved to Purdue.
I asked him a few years later if he ever discussed with William Rowe the passage from Rowe’s book about how Aquinas distinguished between the possibility of a man generating himself to infinity and the impossibility of that series becoming actually infinite. He hadn’t as I think they were working on different things.
When Draper and Plantinga were publishing The Great Debate on the internet infidels website back in 2005-ish, I was arguing on the infidels forum about the distinction Aquinas made. I would probably cringe if I had to reread those conversations today.
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Which is fine as an opinion about the state of things. The question is whether there is objective evidence to back up that viewpoint.
Yes. The deleterious mutation rate is only marginally high in humans – perhaps a factor of a few higher than we could tolerate without any recombination. Recombination lets us deal with that rate. If much less than one percent of that rate escapes the effects of recombination because of clustered recombination, that’s neglibile.
You seem to be supporting the wrong side of the argument here. Recombination in general only happens in very very few places at one time, and yet it’s highly effective at promoting selection against deleterious mutations and breaking linkage between beneficial mutations and deleterious ones. That means it doesn’t matter much exactly where the recombinations occur if a single recombination per generation within a stretch of a hundred million base pairs is effective.
Unlikely why? It seems to me quite the opposite.
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I can think of a few research papers I wrote in university and grad school that would probably make me cringe if I re-read them.
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Insofar as I’m managing to follow this rather technical discussion, I think I get enough to agree with this.
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Mind you, there were geneticists who thought that it was hard to explain how humans could tolerate the load of deleterious we likely acquire. But I always thought that they were working with quite a bad model of how most selection works (and that they would have known if they’d paid attention to what Bruce Wallace wrote in 1970). Eventually, the worried geneticists figured this out for themselves:
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The substance of the conversations was good though. For example, one big thing among the “infidels” was metaphysics is meaningless or unsubstantiated. I did have a particularly good chat with one of the “leaders” there and explained how the three possible statements which may explain the universe are an introduction to metaphysics
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“ϕ depends jointly on U”
Should I know what U is?
“U is the overall rate of deleterious mutation per diploid genome per generation”.
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It seems that they solved the problem by replacing absolute fitness by relative fitness. Relative fitness means that although your absolute fitness decreases, if the mean fitness of others in your population decreases more, you are fine.
Not really. If your relative fitness decreases, it may make the absolute fitness of the population decrease, remain the same, or increase. The main point is that they never should have been using absolute fitness to start with – that’s a model, and not one that describes reality well. Most organisms, at least most organisms like humans throughout most of our history, are limited by external factors. For us, it’s mostly been the carrying capacity of the areas we’ve occupied. That means our ability to reproduce successfully has depended on how well we competed with other for the resources available (and to a lesser extent, how well we avoided predation). So a lot of selection inherently involves relative fitness.
Another way of looking at the situation: humans all carry some number of deleterious alleles. Our ancestors have always carried a similar number, and they’ve done just fine. How fit we are compared to some ideal human with no deleterious alleles doesn’t matter because that human has never existed. As long as we are carrying a substantial number, the difference between someone with a low load and an unfortunate person with a high load is large, meaning that the failure of the latter to reproduce eliminates a large number of deleterious alleles.
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That’s rather vague.
There are certainly lots of papers describing the evolution of crystallin proteins, and they get into the specific features of the proteins. A Google search for “evolution of crystallin proteins” should point you in the right direction. I would have posted a lot of information from those papers, but I get the distinct impression that it wouldn’t have had much of an impact.
Another interesting question did come to me. Do you think the mammalian middle ear is irreducibly complex?
If you remove any one of those three bones the whole structure loses function. So would this qualify?
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You might give me nightmares of comparative anatomy. That was the weed-out course for pre-med in undergrad and following the migration of reptilian jawbones was not joyful, in part because a lot of it was just memory work, and partly because at that point in life, there was still some degree of cognitive dissonance in integrating scientific facts with conservative religious teaching.
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I somehow managed to graduate with honors despite having skipped Human Anatomy, and I have actually had a couple of nightmares that included finding myself in a classroom taking an exam on the subject.
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Could you elaborate a bit more on this, taking into account that deleterious mutations outnumber by far the beneficial mutations?
That is true. For me, this is not a major point of discussion, may be I would have simply accepted them. When we regard the lens as emerging feature. First we have an eye without lens. A fluid filled cavity with a narrow opening in the front and photo receptors in the back. Where do we like to start with, creating a lens? We need to put something in the fluid filled cavity without disturbing the passage of light. Will a cloudy clump of proteins help? Or a flapping membrane?
Does it have to be a series of discreet stages? You could start with photoreceptors already beneath transparent membrane. Transparency is no big effort in nature; after all there exist fish and such that you can see through the entire animal.
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In the classical drawings, it is a series of discreet stages. However, we are not obliged to stick to that view. What might be the function of such a membrane? I don’t think that it improves sight?
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It would have been protective over the more delicate photoreceptor cells. The next step may have been going from simple light/dark detection to determining the direction of the light, which might involve the photoreceptor cells, or the structure of the overlying membrane. All that is supposition of course, but based on reasonable progression, and light sensing ability in lower animals that persists today.
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Yes. Nature seems to like compartmentalizing with membranes, internally with organs, and externally with skin. I recall from decades ago asking one of my preschoolers, “what is the purpose of skin?” Her prompt reply: “it holds us in”. Worked for me.
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