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Author | Topic: Explaining the pro-Evolution position | |||||||||||||||||||||||||||
Dr Adequate Member (Idle past 284 days) Posts: 16113 Joined: |
Thanks Doc. BTW, if you think that fixation and amplification are the same thing ... I don't, which is why I have never said so.
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PaulK Member Posts: 17822 Joined: Member Rating: 2.2 |
I have a question for you Kleinman. Since you militantly refuse to understand rmns how can you possibly know that a proper understanding would falsify evolution ?
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Taq Member Posts: 9972 Joined: Member Rating: 5.5 |
Kleinman writes:
I think you will find some disagreement with other posters on this thread. As long as mutation are random events, beneficial mutations are just a subset of all mutations. I don't see how that addresses anything in my post. Let's use military tanks as an example. Let's say that two possible upgrades for a tank are thicker armor and a more powerful main gun. A tank with either thicker armor or a more powerful gun would be better. A tank with BOTH thicker armor and a more powerful gun would be better than a tank with just one upgrade. The upgrades are additive in that both upgrades add up to a better tank than a single upgrade by itself. This is often how beneficial mutations work. A beneficial mutation is beneficial all by itself. When it is combined with another beneficial mutation, the individual with two beneficial mutations is more fit than an individual with just one of those beneficial mutations. The problem with your HIV model is that it doesn't take this into account. You are only looking at situations where you need both mutations in order to see an increase in fitness. As discussed earlier, this isn't always the case in the real world. Edited by Taq, : No reason given.
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Dr Adequate Member (Idle past 284 days) Posts: 16113 Joined: |
I don't have a reference at hand, but I may find time to find one. I think my example of melanin production and malaria resistance should suffice, unless someone can explain how darker skin will not be selected for unless someone also has mutations that confer malarial resistance (and visa versa). I meant specifically for the bit where you said "the individual viruses with just one potentially beneficially mutation do not reproduce at a higher rate".
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Taq Member Posts: 9972 Joined: Member Rating: 5.5 |
Kleinman writes: Don't get me wrong, there's more than one way replicators can adapt to selection pressures other than rmns. Recombination is a much faster way replicators can adapt and they can do it to multiple selection pressures simultaneously. But they have to have the correct alleles already in the gene pool. Recombination events are random mutations, and recombination events can produce new alleles.
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Modulous Member Posts: 7801 From: Manchester, UK Joined: |
On the other hand, rmns is the creation of new alleles in order to adapt. Yet more evidence I am correct in my assessment of your argument. Random mutations create new alleles. Natural selection does not create new alleles. And NONE OF IT happens 'in order to adapt'. The new alleles are in competition with the other alleles. If it replicates at a faster rate than they, they will increase in frequency - else they won't. That's natural selection. It doesn't create alleles it's just the phenomena that alleles which are able to replicate more, will be more replicated.
And if the adaptation requires the creation of multiple different new alleles at different genetic loci due to multiple different selection pressures simultaneously, the chances of adaptation are extremely low and the process is extremely slow if it going to happen If apply pressure to carbon, will I get a diamond? Surely it depends on the magnitude of the pressure. Why do you assume all pressures are equal in biology?
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Taq Member Posts: 9972 Joined: Member Rating: 5.5 |
Dr Adequate writes: I meant specifically for the bit where you said "the individual viruses with just one potentially beneficially mutation do not reproduce at a higher rate". Sorry for the confusion. With multidrug therapy, if a virus gains a mutation that confers resistance to just one of the drugs it will not be fitter than other viruses without that same mutation. This means that individual viral particles with just one mutation to one drug will replicate at the same rate as those without the mutation.
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Dr Adequate Member (Idle past 284 days) Posts: 16113 Joined: |
Sorry for the confusion. With multidrug therapy, if a virus gains a mutation that confers resistance to just one of the drugs it will not be fitter than other viruses without that same mutation. This means that individual viral particles with just one mutation to one drug will replicate at the same rate as those without the mutation. But do you have a reference for this? It seems like quite an important point, so it would be nice to have something to back it up.
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Kleinman Member (Idle past 335 days) Posts: 2142 From: United States Joined: |
quote:Time is not measured in seconds, minutes, hours for rmns, the measure of time for rmns is replications (generations). And under the right circumstances, the probability of two beneficial mutations occurring on a lineage can go to 1 if there is sufficient amplification (and fixation is not necessary). The reason I answer I don't know to a question is I don't know. And the notion of a beneficial mutation is a slippery thing as well. Sickle cell trait might be beneficial in one environment with Malaria but in an environment without Malaria, at best that mutation is neutral and under some circumstances detrimental. What you can do with calculations like mine are obtain estimates of the upper limits of the probabilities for rmns. Assume that when the mutation occurs at the particular site, it is always the beneficial mutation, that will raise your probabilities slightly but it will not make the multiplication rule go away when more than a single beneficial mutation must occur on a lineage.
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Dr Adequate Member (Idle past 284 days) Posts: 16113 Joined: |
Time is not measured in seconds, minutes, hours for rmns, the measure of time for rmns is replications (generations). Quite: so generation time is also something you'd need to know.
The reason I answer I don't know to a question is I don't know. But why did you say you didn't need to know?
What you can do with calculations like mine are obtain estimates of the upper limits of the probabilities for rmns. Assume that when the mutation occurs at the particular site, it is always the beneficial mutation, that will raise your probabilities slightly but it will not make the multiplication rule go away when more than a single beneficial mutation must occur on a lineage. Again, the probability of that is 1 --- given enough time.
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Kleinman Member (Idle past 335 days) Posts: 2142 From: United States Joined: |
quote:You don't think that the multiplication rule of probabilities is a roadblock? I hope your expectations aren't too high when you buy tickets to two different lotteries and think you are going to win both. You had better buy a lot of tickets. And then if you think about the length of the human genome, 3e9, how many tickets do you need to buy to win all those lotteries?
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Taq Member Posts: 9972 Joined: Member Rating: 5.5 |
Kleinman writes: You don't think that the multiplication rule of probabilities is a roadblock? No more so than having more than one step in a flight of stairs is a problem. All you do is rinse and repeat the same process.
I hope your expectations aren't too high when you buy tickets to two different lotteries and think you are going to win both. You don't have to win both. The descendants of two winners can meet up and combine their winnings. That is how sexual recombination works.
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Taq Member Posts: 9972 Joined: Member Rating: 5.5 |
Dr Adequate writes: But do you have a reference for this? It seems like quite an important point, so it would be nice to have something to back it up. I would think that it would be self evident. Multidrug regimens are designed so that resistance to one drug does not affect the efficacy of the other drugs in the regimen.
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PaulK Member Posts: 17822 Joined: Member Rating: 2.2 |
quote: Quite obviously it is not. To anyone with a proper understanding of probability theory. I already explained why it is not. Do you concede that it is possible to generate sequences of arbitrarily small probability ? Or do you think that there is some limit that can't be passed ? Some minimum probability ?
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ringo Member (Idle past 412 days) Posts: 20940 From: frozen wasteland Joined: |
Kleinman writes:
I asked for a physical roadblock. So far it looks like you've just got the mathematics wrong, so a mathematical roadblock doesn't cut it.
You don't think that the multiplication rule of probabilities is a roadblock? Kleinman writes:
Of course there's nothing to prevent that from happening.
I hope your expectations aren't too high when you buy tickets to two different lotteries and think you are going to win both. Kleinman writes:
But it isn't a question of winning all of them independently. What if the prize in Lottery A is a million tickets for Lottery B?
And then if you think about the length of the human genome, 3e9, how many tickets do you need to buy to win all those lotteries?
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