Okay, so two quick rejoinders. I’ve noticed the more relevant players have left the building (Dr. Stump and Dr. Davis). I’m about finished with this. For gbrooks9: the point is that more mutations are deleterious than are positive. Thus, God is using a mechanism that creates more suffering than advance. Even if it were less, you’d still have Him as the arbiter of suffering vis-a-vis genetics.
For benkirk, the issue of ploidy is just a red herring in the discussion. If your argument were true, then genetic diseases would not arise in individuals. Diploidy would save them. Since that claim is easily refutable, my claim stands. Mutations cause suffering. End of story.
I don’t see Shane’s point. He started out claiming:
“A third aspect is that the classic Darwinian view of selection winnowing out bad mutations and keeping the good ones simply doesn’t match reality.”
He apparently doesn’t realize that selection is incapable of winnowing out a recessive deleterious (even lethal) mutation if the population is large enough. p^2+2pq+q^2 is Darwinian all the way.
[quote=“Shanecolburn525, post:41, topic:4353”]
For benkirk, the issue of ploidy is just a red herring in the discussion. If your argument were true, then genetic diseases would not arise in individuals. Diploidy would save them.[/quote]
No, diploidy saves the population, not all individuals. q^2 > 0, but q^2 is less than q. Population genetics doesn’t get more basic than that.
[quote] Since that claim is easily refutable, my claim stands.
[/quote]Since I didn’t make any such claim, you’re not making sense.
One last time. That has nothing to do with the argument. If rare deleterious mutations can persist in large populations…fine. That’s certainly not a fact in defense of your position. My point is that deleterious mutations arise more frequently (substantially more frequently) than adaptive ones. Recombination and diploidy don’t rescue the situation. If they did, you would be arguing that recombination and diploidy can mask the MORE frequent type of mutation. What would that say for the less common type (adaptive mutations?).
The relevant players leave the building when the conversation descends into endless bickering about one word. I think this conversation is about finished its descent into arguing about arguing (as always happens).
So why not start a fresh topic, drawing on the most interesting bits of this conversation?
[quote=“Shanecolburn525, post:44, topic:4353”]
My point is that deleterious mutations arise more frequently (substantially more frequently) than adaptive ones. [/quote]
Shane,
The whole process is a race of surviving configurations of genetic information … with the ADAPTIVE configurations being defined as those with more offspring and/or more fertile offspring.
Are you trying to define Evolution as impossible, because there are more deleterious mutations than adaptive ones? Humans and all the other creations that are still ALIVE … are mostly alive because our predecessors did better than the predecessors of others.
Oh yes they do! You can be a carrier for a genetic disease/disorder yet not have the disease yourself. The sickle cell gene is a good example. If you inherit the sickle cell gene from one parent and a normal gene from the other parent you will be healthy (because the trait is recessive). But if you inherit the sickle cell gene from both parents you will have sickle cell anemia, which can be deadly.
Actually, having the sickle cell gene from just one parent can be an advantage in areas with lots of malaria! It’s called heterozygous advantage.
Here’s a very good, short video from HHMI that explains the genetics: Malaria and Sickle Cell Malaria. It also does a nice job of briefly explaining how science works.
[quote=“Shanecolburn525, post:44, topic:4353”]
If rare deleterious mutations can persist in large populations…fine. That’s certainly not a fact in defense of your position.[/quote]
Common deleterious mutations persist in large populations too. I don’t think that you understand my position.
I don’t see why.
[quote]What would that say for the less common type (adaptive mutations?).
[/quote]That the ratio of dominant to recessive is much higher for adaptive mutant alleles than it is for deleterious ones, as the latter tend to be hypomorphic or null.
So, new mutations are more likely to deprecate or completely eliminate function; those tend to be recessive. The less common, adaptive mutations are much more likely to be dominant. There are, of course, many exceptions, but the trend is clear.
I do not concede (or frankly even understand) your position relative to my argument. But the entire discussion of rare mutations being disproportionately deleterious and dominate ones being adaptive is moot. Do you acknowledge that cancers and developmental deformities (along with other diseases) occur in a significant proportion of human being? And, that they have genetic links (i.e., are often brought about directly or indirectly through mutation)? I don’t see how you can avoid the obvious. As Polkinghorne has cast it, “it is the nature of cells that they will mutate, sometimes causing cancer.” Thus, as I began, the mechanism causes great harm and suffering, and yet this is God’s way of creating. His way of creating was to drive the vast majority of things to extinction, so that one of the extant millions of species would seek communion with Him? Incidentally, is He finished creating, or are we replaceable in His chosen process?
[quote=“Shanecolburn525, post:52, topic:4353”]
I do not concede (or frankly even understand) your position relative to my argument.[/quote]
That’s interesting. If you don’t understand, what possible basis could you have for refusing to concede anything?
What does “dominate ones” mean? If it’s moot, why did you start the discussion?
You’re amazing.
Back at #26, I asked you to clarify: “I presume that you are limiting yourself to the germ line and ignoring somatic mutation?”
Since you didn’t answer, why are you bringing up somatic mutation (cancer) now?
That’s just hogwash, Shane. Cancer is defined as a genetic disease. It isn’t “often brought about directly or indirectly through mutation,” Cancer is simply ALWAYS CAUSED BY MUTATIONS. Nongenetic factors are sometimes there, but always minor. Most, but not all, of those mutations are somatic, which is why I asked the question you didn’t answer.
I don’t see that you are in any position to know what is obvious and what is not if you think that cancer merely has “genetic links,” instead of being directly caused by somatic mutations.
I’m sorry, but that’s not true. Cancer genesis is fairly well known. In general, it involves the break down of “checkpoints” in the cell cycle, which are regulated by gene-protein interactions networks. You inherit genetic predisposition via particular point mutations at fertilization. You accumulate the others, as a consequence of a diversity of environmental phenomena. I’ve let you ride for a while, but you should know that I’m a little further up the biology food chain than you suspect. It happens that you’re not talking to an untrained pedestrian. But, if’ you’re going to (in typical form for you) equivocate over a typo (“dominate” instead of “dominant”) I think we’re done. I thank every one for their time.
[quote=“Shanecolburn525, post:55, topic:4353”]
I’m sorry, but that’s not true.[/quote]
What exactly is not true?
Yes, but that breakdown is a consequence of new, somatic mutations. Cancer is a genetic disease.
You seem confused. There’s no evidence to suggest that the mutations occur at fertilization, and plenty of predisposing (aka germline) mutations are not point mutations, but deletions. Those predisposing ones are never sufficient; additional somatic mutations have to occur.
[quote]You accumulate the others, as a consequence of a diversity of environmental phenomena.
[/quote]You certainly do accumulate the others, but as a general rule, not as a consequence of the environment; reality is far more complex than that. That’s the case for only a few major cancers, including esophageal and colon cancer in some cultures (diet), melanoma (uv), mouth and throat carcinoma (chewing tobacco) and lung cancer (smoking). For the majority of the others, the baseline mutation rate does the job, and it doesn’t need any bump from the environment. You can isolate yourself from all environmental factors that increase mutation rates and you’re still highly likely to eventually die of cancer.
I still don’t understand what you’re trying to say if you fix the typo.
Brad, I’m pretty certain that all four of us are in complete agreement on the definition of “deleterious.” We’re disagreeing with Shane’s claim about selection, that “…the classic Darwinian view of selection winnowing out bad mutations and keeping the good ones simply doesn’t match reality.” It certainly works in the case of cancer (if “bad” is determined from the perspective of the cell but not the organism), and it certainly does in the case of the population.
It would help greatly if Shane would answer George’s question, “Are you trying to define Evolution as impossible, because there are more deleterious mutations than adaptive ones?”