The End of Evolution By Means of Natural Selection

Happened to catch it in that condition and this is what I think about why it was in that condition, and I still think it.And it only got changed because an idiot creationist's view of it annoyed you.

quote:

---

Yes, but he's saying I'm contradicting YEC views and I know I'm not contradicting that one.

---

In fact what I am saying is that genetic diversity is already too high to be easily explained if the YEC Flood story is assumed - even if we assume that the Ark carried modern species rather than Creationist "kinds". And your insistence that genetic diversity is continuously decreasing makes that problem far worse. This is so clearly true that I cannot see how you could even hope to deny it.

I don't think I deny that it's hard to explain, do I? I know it's hard to explain, I'm simply trying out some possibilities, and I don't think this has to be resolved in order to pursue my current argument.To try to explain it I have to start with the obvious fact that whatever the genetic situation was on the ark it wasn't anything like it is today, and try to imagine possible genetic scenarios that could have been the case. I assume a geneticist would do a better job of it than I do if he could accept the premises for the purpose.

quote:

---

I don't think I deny that it's hard to explain, do I? I know it's hard to explain, I'm simply trying out some possibilities, and I don't think this has to be resolved in order to pursue my current argument.

---

In other words what I am saying IS true, contrary to your assertion.

quote:

---

To try to explain it I have to start with the obvious fact that whatever the genetic situation was on the ark it wasn't anything like it is today, and try to imagine possible genetic scenarios that could have been the case. I assume a geneticist would do a better job of it than I do if he could accept the premises for the purpose.

---

By which you mean that your Flood scenario REQUIRES radical differences to the genetics of the animals on board, differences which somehow produced the diversity we see today. And you don't know enough to construct an answer that is in the least bit plausible. Yet you don't see the need to invoke such massive ad hoc assumptions as a problem in your position ? Since you haven't got any real evidence that genetic diversity is decreasing maybe you should reconsider that assumption instead.

Sorry, I guess I still don't know what you're saying. Yes, of course. Thought a "packed" genome was a pretty good start myself. Not in my current argument. It's a completely separate issue. I'm trying to stick to what I understand to actually occur in the present, whether anybody here thinks I'm right about that or not, I'm not speculating about an utterly different situation in the distant past. It's logical that it's decreasing. There isn't anything else it could do. Even with mutations. Edited by Faith, : No reason given.

quote:

---

Sorry, I guess I still don't know what you're saying.

---

I am saying that if you already have a problem that genetic diversity is too high because of an assumed past bottleneck, arguing that it must also decrease over time only makes the problem worse.

quote:

---

Thought a "packed" genome was a pretty good start myself.

---

Since it only gets you extra genes, not extra alleles for the genes that are retained it doesn't seem to be very helpful. Maybe it would account for related species having some different genes, but that's all. And of course it is pure speculation.

quote:

---

Not in my current argument. It's a completely separate issue. I'm trying to stick to what I understand to actually occur in the present, whether anybody here thinks I'm right about that or not, I'm not speculating about an utterly different situation in the distant past.

---

I don't think that it is a separate issue. If genetic diversity can't increase then it cannot have been lower in the past. And, of course, the only reason why you are saying that it is completely different is because there is a clear problem with current genetic diversity. There's no direct evidence of this alleged difference.

quote:

---

It's logical that it's decreasing. There isn't anything else it could do. Even with mutations.

---

No, it's not logical. It's an unevidenced assumption. Especially as it relies in not counting the increases in diversity from mutation.

quote:

---

I see what you're saying. But I think you're wrong in assuming that large dogs and small dogs can't mate. Yes, it is a physical barrier for a large male dog to impregnate a small female dog. And it is a physical barrier for a small female dog to carry a large dog offspring to term. But if you flip the genders reproduction is easily possible. Other than the fact that the large female dog would have to be laying down, is there any reason why a small male dog physically could not impregnate her? Is there any reason why the large female could not carry a small offspring to term?

​

My wife's old roommate had a rotweiller/dacshund mix. Rotweiller mother, dacshund father. The smaller father had minimal issues impregnating the larger mother and the larger mother had minimal issues carrying the pups to term. The dog grew to be larger than a dacshund but smaller than a rotweiller, a hybrid. A male dog from the litter could easily impregnate another female rotweiller or a female dachshund and then you would have fourth and fifth size variants.

​

Unless there is a mechanism that would create barriers for a large mother/small father combination then I don't think size could be the lone cause of a speciation event. ?

---

Very good points Misha.Do you think the same is true of the smallest and largest dogs, eg chihuahua and great dane? There I can see the logistics being a problem!

I think what Faith is talking about is another form of supergenome. She is suggesting that the initial ancestral organisms, in a flood scenario presumably the breeding pair Noah selected, had very high ploidy compared to modern organisms, and therefore had multiple alleles for each gene. There are some modern animals with high ploidy, particularly the various species of Xenopus which can be up to dodecaploid having 12 sets of chromosomes, but even in this case that would give you a maximum of 24 alleles for every gene.It does rather beggar belief that Faith can at once be so scrupulous as to deny the role of mutation in creating standing variation unless we have expirimentally observed the mutation ourselves, something that is well established and routinely demonstrated, but then put forward totally unsupported mechanisms with not a shred of evidence as if they were a sufficient alternative explanation.TTFN,WK

Very high ploidy? You mean multiple copies of the chromosomes so that there are multiple copies of the genes in those chromosomes, and that in each chromosome the genes contain different alleles so that this could act as a store of many different alleles for each gene, but that except in some flowering plants and some other cases primarily from the plant kingdom all those duplicate chromosomes are now gone but their alleles have been distributed into the sole remaining gene throughout the population.Something like this is what you think Faith is saying? Really? Especially since it would take something like, oh, I don't know, MUTATIONS to eliminate all the duplicate chromosomes, either gene-by-gene or all at once? Are there any examples of a chromosome in the midst of the gene-by-gene loss possibility of chromosome loss?It seems to me that what you've proposed is a scenario in which Faith could have the store of "built in" alleles she needs that would otherwise render her proposal trivially wrong due to the genetic bottleneck of the flood, but which is itself wildly improbable.Apologies for the sarcasm, I've already been Faith'd twice in the past 24 hours, and I despair at the careful explanations I'm going to have to devise for her Message 509 that she'll then not understand, which will make three times.--PercyEdited by Percy, : Typo.

I'm not sure. I don't breed dogs for a living. However, logistically I think the main issue would be ejaculation of the male chihuahua into the female dane. This is where I could see an issue. Is the male chihuahua's phallus large enough to make enough contact with the vaginal wall of the dane in order to induce the ejaculation?Sorry, didn't mean to be so graphic with that. But i can't think of another way to explain it scientifically.

The speed and mobility of sperm is incredible!--Percy

I didn't notice any sarcasm, I think those are exactly the sort of things Faith is proposing, and she isn't the first. Bear in mind that she doesn't seem to have any objection to something like mutation facilitating her fanciful hypotheses, she only seems to object to the existence of beneficial mutations which increase genetic variation in a population. I think all such ad hoc creationist mechanisms are highly prone to the same problem of kind of explaining something but in themselves being wildly improbable.The idea that a creationist will come here with hypotheses that are reasonable, coherent and show any familiarity with biology is itself wildly improbable, I would have thought you had been doing this long enough to realise that?TTFN,WK

You think that was graphic? Be glad you didn't pair them the other way around then. "Ripped to fucking shreds" comes to mind...

Hi, Faith. This has been addressed multiple times already, you just haven’t recognized it as such.When I try to visualize your argument, I think of the old Atari game Asteroids (yes, I am old enough to have played it*). *...if by it, you mean the version that was remade for Windows in the early 1990’s).Have you played that game? When you shoot an asteroid, it breaks into two or more smaller pieces. Then, if you shoot the pieces, they break into two or more even smaller pieces. It continues like this until the asteroid pieces are so small that the next shot disintegrates them.This is very much analogous to your argument, if we think of the size of the asteroids as representing the genetic diversity of distinct populations. When an asteroid (population) is broken into two pieces, the two pieces are smaller (less diverse) than the original asteroid (population). With enough shots, the player can destroy all asteroids on the screen (drive all populations to extinction). This is akin to the process of evolution as you see it happening: reduction by fragmentation until there is nothing left.What this model does not incorporate is the opposite effect. Like you say, IF mutations can create new variations in the population, genetic diversity in the population increases as mutations happen (your words were, ...tends to [make] a mixed multitude of the same species...).An analogy for the game Asteroids would be a game mechanic that allows the asteroids to grow in size over time. Think of the consequences of this: you could shoot an asteroid, breaking it into smaller pieces, and the pieces could subsequently grow until they were as large or larger than the original asteroid. If a player is a poor shot, the asteroids’ growth could easily outpace the player’s ability to break them up, and the player would never be able to clear the screen of asteroids. In fact, the player may end up with many more---and much bigger---asteroids then he started with!This is what we hypothesize about evolution (in a very simple, abstract way): genetic diversity can accumulate before, during and after speciation, because of the inevitable process of mutation. Regardless of what causes speciation/isolation, mutation will happen, and can, in fact, counteract the negative effects of natural selection and genetic drift on diversity.Thus, populations are not necessarily doomed to wallow in shallow gene pools forever: if they can survive genetic bottlenecks, and if new mutations can add genetic diversity, there remains no reason to think they cannot evolve.This is what evolution is all about: mutation to produce more product, and selection to pare it down by functionality. It is fundamentally a question of the rate of accumulation of new alleles versus the rate of extremination of old alleles.Edited by Bluejay, : Small addition.

---

-Bluejay (a.k.a. Mantis, Thylacosmilus)Darwin loves you.

Hi, RAZD. I'm not sure I agree with this part. I can envision porcupine quills as being generated from the same combination of genes that produce our hair, with different patterns of expression.For instance, a mutation that causes overexpression of factors influencing the rate of deposition of fibrous materials in the hair could easily result in stiffer, larger hairs. This could be accomplished by creating the equivalent of a new allele, rather than an entire new gene.Certainly, I'll grant that a new gene could be an important factor in the development of a new feature or structure, but I'm not sure that it's actually necessary.

---

-Bluejay (a.k.a. Mantis, Thylacosmilus)Darwin loves you.