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Author
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Topic: The End of Evolution By Means of Natural Selection
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Percy
Member Posts: 22480 From: New Hampshire Joined: 12-23-2000 Member Rating: 4.8
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Re: I see no sarcasm
Wounded King writes: I didn't notice any sarcasm, I think those are exactly the sort of things Faith is proposing...  I think she would have to understand a great deal more than she does do even understand your interpretation of what she's proposing, let alone describe it.
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? I expect wildly improbably proposals from creationists. This one came from you and caught me by surprise. --Percy
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Faith 
Suspended Member (Idle past 1466 days) Posts: 35298 From: Nevada, USA Joined: 10-06-2001
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Message 527 of 851 (557054)
04-22-2010 12:12 PM
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Reply to: Message 516 by PaulK
04-22-2010 3:11 AM
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Re: This argument doesn't depend on the Bible
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. But I don't have a problem that genetic diversity is "too high." A bottleneck when the diversity was enormously higher than it is today, and the genome had all functioning and no junk DNA, wouldn't have the drastic effect it does now because of the lower diversity in species now. It would have a drastic effect by comparison with what existed before but not anything like it would today.
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. As I said, it's a good start, a good start for a hypothesis, which of course IS speculation. And then there's polyploidy to add to it, which WK just confirmed can supply more alleles, up to quite a large number it appears. And there's still also the farther-out possibility of an ACCURATE and LAW-following sort of "mutation." Yes, it's all speculation.
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. But I don't expect it to be lower in the past, I expect it to be higher in the past. And it is a separate issue because it can be discussed completely separately. I don't have to explain how the genetic situation on the ark could have had enormously higher genetic diversity in order to discuss whether genetic reduction is going on in population splits today.
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. No, it's completely different because if the Flood account is true, genetic diversity has to have started out larger and been running out ever since, which contradicts current assumptions, but it doesn't contradict the argument I am making. It is consistent with what I'm arguing now, as it should be if there's anything to what I'm saying, but I don't need to have an answer to the past in order to argue for progressively reduced genetic diversity now.
There's no direct evidence of this alleged difference. No, it's a hypothesis. You have to start somewhere.
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. It doesn't rely on ignoring mutation, it includes the possibility of mutation even though I don't think mutation does what you all think it does. It still decreases with the processes of reduction even with mutation.
| This message is a reply to: | | | Message 516 by PaulK, posted 04-22-2010 3:11 AM | | PaulK has replied |
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PaulK
Member Posts: 17825 Joined: 01-10-2003 Member Rating: 2.2
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Message 528 of 851 (557057)
04-22-2010 12:28 PM
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Reply to: Message 527 by Faith
04-22-2010 12:12 PM
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Re: This argument doesn't depend on the Bible
quote:
But I don't have a problem that genetic diversity is "too high." A bottleneck when the diversity was enormously higher than it is today, and the genome had all functioning and no junk DNA, wouldn't have the drastic effect it does now because of the lower diversity in species now. It would have a drastic effect by comparison with what existed before but not anything like it would today.
If you didn't have a problem you wouldn't be trying to explain it away with these wild speculations. Which don't even work.
quote:
As I said, it's a good start, a good start for a hypothesis, which of course IS speculation. And then there's polyploidy to add to it, which WK just confirmed can supply more alleles, up to quite a large number it appears. And there's still also the farther-out possibility of an ACCURATE and LAW-following sort of "mutation." Yes, it's all speculation.
In fact polyploidy - highly unlikely as it is - is the BEST of the explanations offered. At least it allows for different alleles at the loci where genes are today ! And it doesn't require any implausible and unevidenced mechanisms either.
quote:
But I don't expect it to be lower in the past, I expect it to be higher in the past.
But without your wild speculations it SHOULD be lower in the past if the Flood story is true.
quote:
And it is a separate issue because it can be discussed completely separately. I don't have to explain how the genetic situation on the ark could have had enormously higher genetic diversity in order to discuss whether genetic reduction is going on in population splits today.
If you are looking for actual EVIDENCE that genetic diversity really is declining and is not being replenished by mutations then past diversity does need to be considered.
quote:
No, it's completely different because if the Flood account is true, genetic diversity has to have started out larger and been running out ever since, which contradicts current assumptions, but it doesn't contradict the argument I am making.
That is completely false. There is NOTHING in the Flood account which requires a higher diversity immediately following it. And in fact it strongly suggests that genetic diversity was far lower at that time. Your speculations are an attempt to counter that fact, they are not part of the Flood story at all.
quote:
It doesn't rely on ignoring mutation, it includes the possibility of mutation even though I don't think mutation does what you all think it does. It still decreases with the processes of reduction even with mutation.
As I said your argument relies on assuming that the increases in diversity from mutation do not count. Because if you did count that you would have to compare the rate of loss with the rate of gain to know whether diversity was increasing decreasing or staying the same. That point was raised in the original thread and you haven't yet dealt with it (and please don't refer me to the OP, because that DOESN'T answer it).
| This message is a reply to: | | | Message 527 by Faith, posted 04-22-2010 12:12 PM | | Faith has not replied |
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Faith
Suspended Member (Idle past 1466 days) Posts: 35298 From: Nevada, USA Joined: 10-06-2001
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Re: Mutations Revisited 2 - super-pac magic animals
... Someone had suggested polyploidy at one time so I consider that a possibility for how their genome was different from ours. ... Which still does not produce new genes nor new alleles, it is a mutation that duplicates whole genes.
I think what Faith is talking about is another form of supergenome. Yes, and it's a bit more refined than the supergenome I had in mind last time I was here. Now I have a "packed" genome knowing that at least one creature now has such a thing, bacteria, which is a genome with no junk DNA. I'd wondered about that for some time and now I see it really happens (It also suggests that bacterial genetics should be appreciably different from that for the rest of creation that is getting along on a severely reduced genome full of dead genes.) So it is reasonable to suggest it used to be the case since it very much supports the ark scenario.
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. Noah had three sons with their wives on the ark so that increases the possibilities quite a bit at least for the human race. And there's also no reason to limit the possibilities for any animal in their time by anything in our time. I THOUGHT polyploidy could supply many alleles but wasn't completely sure, so I thank you for verifying that. It does make polyploidy a strong hypothesis for this scenario.
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. But I'm not doing that. I'm proposing possibilities to explain an ancient scenario, I'm not claiming to know how it happened. You on the other hand flatly assert as fact that mutations are the source of all alleles although the actual evidence is extremely scanty for any such claim.
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Faith
Suspended Member (Idle past 1466 days) Posts: 35298 From: Nevada, USA Joined: 10-06-2001
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Message 530 of 851 (557059)
04-22-2010 12:36 PM
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Reply to: Message 519 by Percy
04-22-2010 9:13 AM
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Re: Mutations Revisited 2 - super-pac magic animals
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.
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? He's right, that is indeed what I had in mind though I was hesitant to spell it out. He's now confirmed that it could work.
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? Why not? Destroying genetic material appears to be what mutations do. The remnants are possibly to be found among the junk DNA. Or just gone I guess since our genome is very empty compared to that of bacteria. 95% of our genome junk DNA? Lot of dead genetic material there.
Are there any examples of a chromosome in the midst of the gene-by-gene loss possibility of chromosome loss? That would be interesting to know and if anyone knows it I would assume it would be WK.
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. All scenarios to explain the necessary higher diversity on the ark are going to appear to be wildly improbable and trivially wrong by the uniformitarian assumption based on what happens today.
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. Well, I get "Percy'd" regularly here so let's call it a draw.  Edited by Faith, : No reason given. Edited by Faith, : No reason given.
| This message is a reply to: | | | Message 519 by Percy, posted 04-22-2010 9:13 AM | | Percy has replied |
| Replies to this message: | | | Message 547 by Percy, posted 04-22-2010 4:52 PM | | Faith has replied |
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Faith
Suspended Member (Idle past 1466 days) Posts: 35298 From: Nevada, USA Joined: 10-06-2001
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Re: I see no sarcasm
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 didn't notice any sarcasm, I didn't either.
I think those are exactly the sort of things Faith is proposing, and she isn't the first. And you are right.
Bear in mind that she doesn't seem to have any objection to something like mutation facilitating her fanciful hypotheses, But a different sort of mutation, not what we see today if you mean the proposal for generating alleles from the ark. But I like polyploidy better now for the explanation of the abundance of alleles. And since what we see today is mostly destructive mutations, THOSE I can see operating to produce all that junk DNA we've accumulated down the millennia.
she only seems to object to the existence of beneficial mutations which increase genetic variation in a population. No, I object to the paucity of empirical evidence for that claim. And nevertheless I'm accepting it for the sake of argument.
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. By current standards they are wildly improbable, but a creationist doesn't accept current standards.
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? But I do know what polyploidy is and I do know what mutations are and I do know what junk DNA is and I do know what gene duplication is and I do know what natural selection and drift and migration do. Not as an expert knows these things but I do know them.
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Faith
Suspended Member (Idle past 1466 days) Posts: 35298 From: Nevada, USA Joined: 10-06-2001
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Message 532 of 851 (557062)
04-22-2010 1:02 PM
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Reply to: Message 524 by Blue Jay
04-22-2010 10:31 AM
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Re: Playing Atari
Faith writes:
If that's my "whole model," then why hasn't anyone addressed it to show that speciation can occur with allele increase? I've maintained over and over that it can't, that new variations depend on isolation and reduction and increase only tends to a mixed multitude of the same species without creating new variations -- but except for asserting over and over that I'm wrong I don't recall a single attempt to prove it. This has been addressed multiple times already, you just haven’t recognized it as such. I've only seen it asserted and even screamed at me.
When I try to visualize your argument, I think of the old Atari game Asteroids (yes, I am old enough to have played it*). 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. It's the most superficial possible description of the argument ignoring the genetic dynamics that occur with each split.
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. No.
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. Bluejay, you are NOT getting it at all and the fact that you THINK you are getting it is really frustrating. You are not screaming this mind-cramping simplistic typical answer to me, but you are simply asserting it over and over and over. I have to leave in a few minutes but I would like to TRY to give you a better answer although I would have thought I've answered this many times over by now. I'll have to come back to try again.
| This message is a reply to: | | | Message 524 by Blue Jay, posted 04-22-2010 10:31 AM | | Blue Jay has replied |
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Blue Jay
Member (Idle past 2719 days) Posts: 2843 From: You couldn't pronounce it with your mouthparts Joined: 02-04-2008
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Message 533 of 851 (557063)
04-22-2010 1:04 PM
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Reply to: Message 527 by Faith
04-22-2010 12:12 PM
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Re: This argument doesn't depend on the Bible
Hi, Faith.
Faith writes: Yes, it's all speculation. Which, in the case of your arguments, is totally acceptable. But, for us, nothing short of absolute, firsthand proof is good enough. This is a double standard, and it really pisses me off. The way to determine which of two hypotheses is superior is to compare the fuzzy or speculative bits (all hypotheses, generally, will have some) and determine which hypothesis has the least outlandish baggage. So, we're comparing the feasibility of mutations outpacing selection over millions of years in a replicable fashion that rather handily matches some processes we actually see occurring in genomes today... to the feasibility of polyploid animals slowly losing entire, intact sets of chromosomes over thousands of years in an almost unprecedented and inconfirmable fashion that is no longer observed (or even expected) to occur in genomes today. This simple comparison is why the Theory of Evolution is pretty much universally regarded by scientists as the superior explanation for the diversity of life on Earth: even though it's not perfect, it minimizes the baggage.
-Bluejay (a.k.a. Mantis, Thylacosmilus) Darwin loves you.
| This message is a reply to: | | | Message 527 by Faith, posted 04-22-2010 12:12 PM | | Faith has replied |
| Replies to this message: | | | Message 534 by Faith, posted 04-22-2010 1:13 PM | | Blue Jay has seen this message but not replied |
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Faith
Suspended Member (Idle past 1466 days) Posts: 35298 From: Nevada, USA Joined: 10-06-2001
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Message 534 of 851 (557068)
04-22-2010 1:13 PM
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Reply to: Message 533 by Blue Jay
04-22-2010 1:04 PM
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Re: This argument doesn't depend on the Bible
Faith writes:
Yes, it's all speculation. Which, in the case of your arguments Which, in the case of your arguments, is totally acceptable. But, for us, nothing short of absolute, firsthand proof is good enough. This is a double standard, and it really pisses me off. I am NOT arguing from speculation about the subject of this thread, Bluejay. What I'm saying is speculative is the SIDE ISSUE of what the genetic situation was on the ark. That is NOT the topic of this thread, though others insist on bringing it up so I offer my speculations. And again, when mutations as the source of all alleles is treated as FACT although the evidence is so scanty, you are committing something far worse than speculation. Speculation is honest. You OUGHT to consider that a speculation and NEVER present it as a fact as you all do.
| This message is a reply to: | | | Message 533 by Blue Jay, posted 04-22-2010 1:04 PM | | Blue Jay has seen this message but not replied |
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misha
Member (Idle past 4649 days) Posts: 69 From: Atlanta Joined: 02-04-2010
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Message 535 of 851 (557070)
04-22-2010 1:24 PM
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Reply to: Message 529 by Faith
04-22-2010 12:28 PM
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Re: Mutations Revisited 2 - super-pac magic animals
WK writes: 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. However, through this Faith is also suggesting that almost every vertebrate and more specifically every known mammal except for one rare Argentinian rat (tetraploid) has undergone the a level of "ploid" reduction resulting in the almost unanimous diploid scenario we see currently. However, during this decrease her humans would have not undergone any speciation events where as every other animal would have. Also no more "ploid" reduction would be available in the future unless these future creatures are uniploid/asexual. The sheer mental gymnastics required to adhere to such an illogical and unfactual stance is ridiculous.
| This message is a reply to: | | | Message 529 by Faith, posted 04-22-2010 12:28 PM | | Faith has replied |
| Replies to this message: | | | Message 539 by Faith, posted 04-22-2010 3:28 PM | | misha has not replied |
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Iblis
Member (Idle past 3917 days) Posts: 663 Joined: 11-17-2005
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Message 536 of 851 (557071)
04-22-2010 1:40 PM
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mutations as disease, yet causing speciation?
I still haven't managed to digest the polyploidy and "junk DNA" as lost alleles arguments, so forgive me for not incorporating those arguments into my "simulation" as of yet. But I see that Faith is allowing for mutation to happen, as long as it's in the form of disease and degeneration. There are a lot of diseases and disorders that directly affect the chromosomes, aren't there? I am thinking of things like Down's Syndrome, dwarfism, and hermaphroditism of various kinds. Chromosomes can fuse, split, double, or vanish. These sort of "disease" mutations could certainly contribute to speciation couldn't they? For example, we have horses and donkeys. We know they are the same "kind" because they can interbreed. These pairings are not very successful, however, they produce mules which usually cannot reproduce in turn. The occasional non-sterile mule or hinny still won't breed true, they revert to one type or another. The reason for this is that horses have 32 chromosome pairs (64 chromosomes) while donkeys have only 31 pairs (62.) As a result, the mule only has 63 chromosomes, which don't pair up properly for further reproduction. Now, isn't this a result of what we would certainly call disease if it happened to us? That is, either the horse ancestors suffered a chromosome fusion or loss which produced the donkey, or else vice-versa the donkeys suffered a split or doubling. Yes? So if something a little more severe than this happened to animals of a particular kind, they very well might not end up being able to interbreed at all. Yet they would obviously still be basically the same animal, as with hares and rabbits or whatever, camels and llamas, sheep and goats, bison and cattle; we see lots of unlikely breeding pairs and also animals who look the same to us but cannot interbreed. Isn't this mutation / defect at the chromosome level the cause of a lot of this?
| Replies to this message: | | | Message 540 by Faith, posted 04-22-2010 3:34 PM | | Iblis has not replied | | | Message 553 by RAZD, posted 04-22-2010 7:22 PM | | Iblis has not replied |
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Blue Jay
Member (Idle past 2719 days) Posts: 2843 From: You couldn't pronounce it with your mouthparts Joined: 02-04-2008
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Message 537 of 851 (557074)
04-22-2010 1:56 PM
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Reply to: Message 532 by Faith
04-22-2010 1:02 PM
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Re: Playing Atari
Hi, Faith.
Faith writes: It's the most superficial possible description of the argument ignoring the genetic dynamics that occur with each split. Yes, my analogy is very simple: it compacts speciation down into a single, clean instant, and ignores the exact identity of the genetic diversity that is added by mutation. But, it was not meant to be a mechanistic analogy: it was only meant to be an analogy of the consequences of speciation and mutation, when they both are happening in the same system. Since you agreed to assume that mutations happen, for the sake of argument---
Faith writes: WK writes: she only seems to object to the existence of beneficial mutations which increase genetic variation in a population. No, I object to the paucity of empirical evidence for that claim. And nevertheless I'm accepting it for the sake of argument.
from Message 531 --- then the mechanistic discussion is over, and all we are discussing now is the consequences of these processes, which the Asteroids analogy captures sufficiently well for our utility. Speciation can be as messy, as dynamic and as devastating as you want it to be, but, the consequences are still the same: isolated populations and, if mutation is included, subsequent and/or prior addition of genetic diversity. When you finally accept that this is the case, we can proceed to discuss whether or not mutation rates can outpace selection rates. If you do not accept this, then you can go back through the circle again (with someone else this time), or you can try to defend your obstinance in not accepting it, rather than simply claim that the evidence that we have provided is not there.
-Bluejay (a.k.a. Mantis, Thylacosmilus) Darwin loves you.
| This message is a reply to: | | | Message 532 by Faith, posted 04-22-2010 1:02 PM | | Faith has replied |
| Replies to this message: | | | Message 541 by Faith, posted 04-22-2010 3:46 PM | | Blue Jay has replied |
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Dr Adequate
Member (Idle past 306 days) Posts: 16113 Joined: 07-20-2006
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Message 538 of 851 (557075)
04-22-2010 2:17 PM
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Reply to: Message 529 by Faith
04-22-2010 12:28 PM
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Re: Mutations Revisited 2 - super-pac magic animals
Yes, and it's a bit more refined than the supergenome I had in mind last time I was here. Now I have a "packed" genome .. So, I was wondering, are there any limits on your fantasy genetics? Is there, for example, anything to stop all mammals from evolving from one "packed" mammal, one supermammal? Remember that the goal of creationists is to deny the obvious fact that evolution has happened in the past, not to deny the obvious fact that it is happening now and that it will happen in the future. In your fantasy world there seems to be nothing preventing evolution from having happened in the past just as scientists assert that it has done. In the end, all your falsehoods and fantasies do not seem to give you a way to deny the very fact that you want to deny. Your bullshit would restrict the possibility of evolution in the future, but the fact that you want to deny is that it has happened in the past.
| This message is a reply to: | | | Message 529 by Faith, posted 04-22-2010 12:28 PM | | Faith has replied |
| Replies to this message: | | | Message 542 by Faith, posted 04-22-2010 4:03 PM | | Dr Adequate has replied |
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Faith
Suspended Member (Idle past 1466 days) Posts: 35298 From: Nevada, USA Joined: 10-06-2001
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Message 539 of 851 (557085)
04-22-2010 3:28 PM
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Reply to: Message 535 by misha
04-22-2010 1:24 PM
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Re: Mutations Revisited 2 - super-pac magic animals
WK writes:
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. However, through this Faith is also suggesting that almost every vertebrate and more specifically every known mammal except for one rare Argentinian rat (tetraploid) has undergone the a level of "ploid" reduction resulting in the almost unanimous diploid scenario we see currently. Apparently that does logically follow, yes.
However, during this decrease her humans would have not undergone any speciation events where as every other animal would have. Yes, if you mean having developed any lines that can no longer interbreed with others. But there were three human couples on the ark, only a pair each of the animals -- except for the clean animals of which there were seven each -- but the point of that was to provide sacrifical animals and if Noah and his family used them for that purpose they probably didn't go on to multiply. Not sure about that. If they did then they had many more genetic possibilities than the people. The situation today is that all human beings are interfertile.
Also no more "ploid" reduction would be available in the future unless these future creatures are uniploid/asexual. Very likely, yes. You seem to get the picture.
The sheer mental gymnastics required to adhere to such an illogical and unfactual stance is ridiculous. Oh it's quite logical and you yourself get it well enough. No more mental gymnastics involved than trying to understand anything in genetics. You just don't like it. As for "unfactual," some facts that fit at least part of what you said are that human beings are all interfertile while there are many species of animals that cannot interbreed with others of their kind.
| This message is a reply to: | | | Message 535 by misha, posted 04-22-2010 1:24 PM | | misha has not replied |
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Faith
Suspended Member (Idle past 1466 days) Posts: 35298 From: Nevada, USA Joined: 10-06-2001
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Message 540 of 851 (557087)
04-22-2010 3:34 PM
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Reply to: Message 536 by Iblis
04-22-2010 1:40 PM
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Re: mutations as disease, yet causing speciation?
I still haven't managed to digest the polyploidy and "junk DNA" as lost alleles arguments, so forgive me for not incorporating those arguments into my "simulation" as of yet. But I see that Faith is allowing for mutation to happen, as long as it's in the form of disease and degeneration. Yes, certainly. But I did also suggest the rather wild possibility that there was once a functioning sort of mutation that did produce alleles. I don't really need that idea any more though, now that a packed genome and polyploidy are available.
There are a lot of diseases and disorders that directly affect the chromosomes, aren't there? I am thinking of things like Down's Syndrome, dwarfism, and hermaphroditism of various kinds. Chromosomes can fuse, split, double, or vanish. Even vanish. There you have it.
These sort of "disease" mutations could certainly contribute to speciation couldn't they? For example, we have horses and donkeys. We know they are the same "kind" because they can interbreed. These pairings are not very successful, however, they produce mules which usually cannot reproduce in turn. The occasional non-sterile mule or hinny still won't breed true, they revert to one type or another. The reason for this is that horses have 32 chromosome pairs (64 chromosomes) while donkeys have only 31 pairs (62.) As a result, the mule only has 63 chromosomes, which don't pair up properly for further reproduction. Now, isn't this a result of what we would certainly call disease if it happened to us? That is, either the horse ancestors suffered a chromosome fusion or loss which produced the donkey, or else vice-versa the donkeys suffered a split or doubling. Yes? You make very good points, Iblis, thank you.
So if something a little more severe than this happened to animals of a particular kind, they very well might not end up being able to interbreed at all. Yet they would obviously still be basically the same animal, as with hares and rabbits or whatever, camels and llamas, sheep and goats, bison and cattle; we see lots of unlikely breeding pairs and also animals who look the same to us but cannot interbreed. Isn't this mutation / defect at the chromosome level the cause of a lot of this? I think you're right about some of it, but I also think that the stopping of interbreeding in some cases is just a natural playing out of natural genetic processes. But it's worth more discussion.
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