Posted on 01/31/2003 4:19:03 PM PST by jennyp
No. Let's look at how the original one was done:
I thought my explanation in #41 was quite clear, and I can't make it any clearer: Britten's original study, by its nature, would never be able to detect sequence differences due to insertion or deletion mutations. The new technique can, and found an extra 3.9% difference in the sequences. But since a single insertion or deletion mutation can affect hundreds or thousands of base pairs with a single mutation, the extra sequence differences add a miniscule amount to the number of mutations necessary to account for them.
Which is why there are 42 million mutations separating us from the chimps, which caused 150 million base-pair differences.
As we have seen, interbreeding often is limited to the members of local populations. If the population is small, Hardy-Weinberg may be violated.
I am well aware of such statements being made by numerous evolutionists. I reject them because they contain numerous half truths. The first half truth (and a half truth is really a complete lie that because it contains and element of truth makes it more believable and thus a better sounding lie) is the implication that while Hardy-Weinberg can be violated in a small population, this makes it likely that a neutral mutation will take over the whole species from that blast off point is false.
You know, I'll bet that Hardy-Weinberg were two evolutionists! In fact, I'll bet they knew quite well that their equations were only valid for large populations.
Let's continue with the example of the population of a million in the species and let's say that the 'tribe' of 100 gets a neutral mutation and it spreads through it. Well, if the 'tribe' gets mixed into the general population (somehow, sometime, somewhere) then Hardy-Weinberg will be in effect again and those carrying the neutral mutation will be only 1/10,000 of the species and will remain so BECAUSE THIS MUTATION IS NEUTRAL. So again this neutral mutation will not take over the population or even become a significant part of the overall genome pool of the species. So this argument is bunk.
No, you're assuming the population of 1 million consists of 1 semi-isolated tribe of 100 and another mass of 999,900. I'm talking about a species that tends to live in tribes in the first place. So we're talking about a species of 1 million individuals who are split up into 10,000 tribes of 100 each. Every time the mutation gets introduced into a new tribe, it has just as good a chance of fixating within that tribe as it did in the first tribe.
There is an even bigger problem though with these mutations becoming through a small inbred group a part of the genome pool of the whole species. It is a scientific fact that harmful mutations far exceed all other mutations. It is a scientific fact that inbreeding is harmful for the tightly inbred group. What this means is that the inbred group will become much less viable due to the inbreeding and that any neutral mutations within it will (if the group does not die off due to the harmful mutations) will dissappear when (or if) it joins the larger group and those harmful mutations show that the inbred group is less viable and less 'fit' than the main group.
No, the scientific fact is that most mutations are neutral. You're thinking of the mutations that have some effect on the organism - they are mostly harmful. But virtually all of the harmful mutations aren't counted among the 42 million mutations that separate us from chimps anyway, since the proto-chimps & proto-humans who carried those mutations quickly died out. I think we can safely assume all those 42 million mutations were either neutral or beneficial. (Almost all of them neutral.)
As for inbreeding, you're now forcing yourself to argue that any species that habitually lives in tribes will die out! That's just absurd.
Are you two busy, or do you just have no estimates? To determine if the differences between man and chimp are reasonably due to chance we need defensable estimates on two things:Hmmmm... I don't think they'll ever know something like that with any degree of specificity. How could they?1) How big was the early population of humans and 2) How many population bottlenecks did humans go through (times when they were reduced to less than a 20 breeding members.
See, here is where we start to disagree. There are several theories for population bottlenecks, none of them definitive yet. For example, see here for the theorized European bottleneck, or the recent FR thread on the Asian descendents of Ghengis Kahn, and I would tend to doubt (a prejudice, I grant) a 20-count human population anywhere but at the very beginning of the species.
The "Out of Africa" theory is, from what I've gathered, just a start to human population history. If we base this exercise on human population bottlenecks for gene fixation, then we are necessarily limited on the conclusions we can draw. I propose a different strategy: We KNOW that chimps and humans are different. The question we are trying to answer, I think, is how did that happen?
I think it would be more informative to identify, investigate, and expand upon the mechanisms of genetic variation. To claim that the chimp-human differences are due to chance is, IMO, to miss an investigative opportunity. "Chance" is not a mechanism. For that matter, neither is "Designer." Gene duplication and replication errors during meiosis and mitosis-- THOSE are mechanisms. The recent work on the role of virii in altering the genetic code is reported to be extremely interesting. For your side, if a Designer did the work, HOW did he do it, are we be able to distinguish "Designed" genetic change from that which occurs naturally, and if so, how would we go about doing that?
I did not say it was not clear, I said it was wrong. As I said, the proof of the pudding that the 5% is indeed the real genetic difference between man and chimp is that Britten, who had done the original study claiming the 1.5% or so, refuted himself. The question has always been about the genetic difference between the two. As I showed you also, the person who wrote the article you are following is a hack with no credibility. No legitimate scientist can say any longer that non-coding DNA is junk like that guy said.
You know, I'll bet that Hardy-Weinberg were two evolutionists! In fact, I'll bet they knew quite well that their equations were only valid for large populations.
Yup, Hardy, Weinberg, Fisher and Wright, the most famous figures in population genetics were all evolutionists. They worked for decades trying to figure out a way to get out of the problems posed by Mendelian genetics to the theory of evolution. They were pretty good mathematicians, but since they were lacking the scientific basis to apply their mathematical ideas they were very wrong. Specifically the problem came about with the discovery of DNA. The problem DNA posed was quite simple and quite awesome. It disproved for good the idea that one single mutation could effect a great change in function. With a single base pair being the result of a mutation, new species from one mutation became totally impossible. Evolution had always assumed that just one change could effect a large change in a species. The population geneticists, working on that assumption believed that a single mutation could have a large enough change in the selectivity to overcome the stasis of Hardy-Weinberg. However, with DNA showing that you would need numerous favorable mutations to achieve any significant change. These mutations would be first of all be subject to being unfavorable and kill the organism, secondly be neutral and be very likely to die off soon after arising, and the few, few favorable ones, because they had such a low or non-existent selective value until many more mutations would be added to it, would also face a high degree of chance of being lost.
What all the above means in essence is that since mutations start in a single organism:
1. Hardy-Weinberg makes the spread of mutations very unlikely to the whole population.
2. Neutral and slightly favorable mutations (those with a low selection coefficient) are likely to not only not spread, but to die off completely within a few generations.
3. And here's the kicker - because due to DNA insuring that a single mutation cannot have any large effect on an organism, all mutations are essentially neutral mutations and likely to die within a few generations.
The only 'out' from the above problem proposed by evolutionists (like you are doing here), is the small inbred population. There is a good scientific reason why calling someone an 'inbred' is an insult. Inbreeding causes harmful mutations to thoroughly make the inbred population less viable. That's a scientific fact and there is no talking their way out of it for evolutionists.
And all that tells us is that we probably don't know everything about the mechanisms of genetic variation yet. This in no way strengthens any other particular hypothesis.
C-man is forced to appeal to some mystery virus.
You are appealing to incredulty to make your case. I bring up viral action as a mechanism of variation. "Mystery" is YOUR addition. Sentis is the one who originally referenced the recent work in virus-induced variation, so I am pinging him to the thread. I believe Nebullis may also be able provide some information on the topic.
Chimps and humans are genetically different. I'm saying let's try to figure out how it happened. 42 million differences? Great! First, are we sure, and second, how do we get there from here (or, how did we get here from there)? I read your posts as suggesting that a natural explanation is impossible.
The mutational burden, so to speak, of the human-chimp difference doesn't rest on the human branch alone. The chimp branch also diverged from a common ancester. So, the numbers shrink further.
Are those numbers reasonable from what we know about mutation rates in humans, today? Yes. Researchers studied the mutation rate at a number of different loci and found that these rates agree with the rates implied by the human-chimp genetic difference.
True, and Condorman pointed that out. jennyp already had that one covered though, she is using 10 million year divergence instead of five million to take into account that you have two groups that are diverging. All of these estimates that we are making have that factored in.
Along with "C", I will be glad to take a look at any link you have on human mutation rates. I would especially like to know about the FIXATION of such mutations in the population.
I don't mean the fixation of some existing Alelle in some sub population, but a truly novel mutation establishing itself in a group. That is what we need to know, not just the mutation rate, but the novel mutation rate, and not just the novel mutation rate, but the fixation rate.
Molecular clock estimates range from 5-8 million years from the human-chimp ancestor. A conservative estimate of 5 million years ignores the recent circa 7 million yo hominid find. It doesn't change much regarding the estimates of about 1% difference in coding regions between chimps and humans. That difference is perfectly reasonable with what we know about mutation rates.
I would especially like to know about the FIXATION of such mutations in the population.
I invite you to do your own homework. You might not be aware, but within that percentage difference, neutral substitutions, that is, mutations that are not fixed, are included.
Here I am. :)
It all boils down to what one chooses to believe. Some scientists claim they have always 'known' something, then when questioned, you find out they only assumed it.
That is a lot to hang on one find that may or may not have that age. I am using numbers provided by jennyp and agreed to by Condorman. They will attest I'm sure that I have been more than fair on the numbers, giving in to their own numbers at every turn.
It doesn't change much regarding the estimates of about 1% difference in coding regions between chimps and humans. That difference is perfectly reasonable with what we know about mutation rates.
I don't see where it is reasonable. I know some mtDNA regions are hyper mutational, but not chromosomal DNA. I don't see how the observed difference squares with the H-W laws we have been discussing on this thread. Even the outrageous pro-evo assumptions I made generate a differece of less than 1% of the observed differences (400K vs. 42 million). And its not 1%, its AT LEAST 1.4% (a 40% difference) in useful genes alone even if all of the non-coding genes are true junk, which is unlikely.
I invite you to do your own homework
Since when is supporting evolution MY homework? The assignment falls to those who proclaim evolution. My homework has convinced me that the scenarios needed to close the gene gap by known natural causes in the time allowed are unreasonable. You were invited to this thread by C-man in hopes that you had some hard data that indicated otherwise.
If you in fact have such data, you might as well present it. If not, I think it is fair for thread participants and observors to conclude that the chimp-man common ancestor hypothesis is unlikley.
within that percentage difference, neutral substitutions, that is, mutations that are not fixed, are included
OK, let's make sure we are meaning the same thing by our terms. I consider a gene pattern "fixed" when it is found throughout a population, regardless of whether it is neutral or helpful.
If you are arguing that all 1.42 million fixed differences are favorable rather than neutral then you are arguing gore3000's original position. It was one of the things that I gave in on, as jennyp argued that the 1.42 million represented fixed neutral as well as favorable mutations.
If there are that many FAVORABLE mutations fixed, then there must have been thousands of times that many neutral ones. That makes the chimp-man scenario even more unlikely.
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