Yorzhik said:
I'll re-state.
The organism with an advantage would be selected and their genes would propagate through the population. Thus, wouldn't this selective advantage be translated into a general advantage?
Well, that’s trivial and probably irrelevant. Trivial if all you mean by “general advantage” is “something that allows a gene to spread in a population,” because that’s kinda the definition of “selective advantage.” Irrelevant in that it has no bearing on what I understood to be the original question, in which an individual in a generally superior, generalist ancestor population acquires a mutation that improves its ability to function in one habitat/environment/respect but hurts its ability to function in all others.
Yorzhik said:
Yes. Consider; you go to a table in Vegas where you gamble at odds where you lose, statistically, 999,999 out of 1,000,000 times. If someone were to say "you only lose at that table", would you tell them "no"? The point being that you could win one time maybe. But in life you have to keep playing, the cells keep reproducing and the mutations keep piling up - you have play at those odds over and over and over. "Only" would be the correct word.
Not in an evolutionary sense. Under normal (read environmentally constrained) conditions, each of those 999,999 deleterious mutations would have an extremely slim chance of persisting, whereas that millionth, beneficial, mutation would have a much better chance of persisting. Interesting how easily you reverse your thinking here. A given mutation is “most likely” deleterious, which you equate with “only” deleterious, and yet mutations that are really really “most unlikely” to persist in the face of natural selection (remember, the probability of fixation of a deleterious mutation in the face of selection is by definition very much worse than chance) are not only not impossible, but are a certainty (your appeal to “mutational load”). What’s up with that?
Yorzhik said:
Yes, that is why I said "by certain definitions". I'm just trying to cut down on the evo weasel factor.
Spare me the mirror. I’m long past taking seriously claims of evo weaseling when creationists uniformly invoked it after making sweeping generalizations, baiting-and-switching, etc. I could write a book on logical fallacies entirely illustrated with creationist examples, but who would care?
Yorzhik said:
The quote I was responding to:
really sounds like it is referring to the parents vs. the children.
Really? I was presenting a pretty basic idea. If the original forms were advanced, and modern forms are less so, then somehow the advanced forms had to have been replaced by the less advanced forms. As I mentioned, unless the offspring of advanced forms were all and equally defective, it's not clear how this replacement could happen. Especially the innumerable times you are implying.
Yorzhik said:
Which is hypothetically OK. Even so, I still answered the question when I said "less advanced forms were not always so bad as to be selected out every generation".
That doesn't answer the question at all. For less advanced forms to not only persist, but spread and become fixed, in the population, they would have to be considerably better than "not always so bad."
Yorzhik said:
Mutational load will eventually catch up with every group.
No, see, that’s the assertion you need to be demonstrating. You don’t demonstrate it by repeating it. You’ll do better to avoid borrowing pages from bob b’s playbook. Think selection intensity.
Yorzhik said:
It should be obvious. Luck and chance happen to us all. The more fit individual will not necessarily survive maybe because they just happened to be standing in the wrong place at the wrong time and get struck by lightning.
I can’t believe you seriously think the role of chance is not taken into account. Silly us! Look, let’s go back to Vegas for a second. The casinos loudly advertise their favorable odds (at least they used to, haven’t been there in decades), odds far, far, far, far better than those we’re talking about here. "You’ve got a 49.5% chance of winning at keno." And yet, the income pours into the casino with at least the same predictability (and far greater amounts) than it does at your average grocery store. Luck may help, or hurt, one individual, but the law of large numbers is an utterly formidable opponent for a defective genotype in a selective environment.
Yorzhik said:
Factors on who survives and who doesn't change so rapidly, that "who is the most fit to survive" can change daily.
Daily, eh? Don’t you think you’re rather desperately overstating your case?
Yorzhik said:
Difficult or not, mutational load will eventually win out in the end in all groups.
Well, when you feel like defending, rather than merely repeating, this assertion, let me know. And please at least acknowledge that the outcome will likely be different in a selected vs. nonselected population, and as you're doing that take a guess as to which state characterizes most populations most of the time.