Syamsu's Objection to Natural Selection...

Well as has already been pointed out, there are a number of differences between animals produced by cloning from the same source. Similarly monozygotic twins are not truly identical.

another source of random phenotypic variation is random X inactivation in females. A given cell during female embryogenesis will inactivate one or the other X chromosome...the process is random (though there are cases when there is skewed X inactivation). An example of profound consequence are heterozygous females who suffer from Deuchennes muscular dystrophy. Normally by having a normal copy of the gene and the mutated form is not enough to cause disease...however, if by chance more than 50% of the cells inactivate the good X chromosome (dont't know what the threshold is..it is also probably variable) the person will grow up suffering from muscular dystrophy though milder than full blown DMD....imagine a coat color gene on the X chromsome with two or more variants for the gene and the resultant coat color pattern...you could keep producing females generation after generation without producing the same coat color pattern...it would not be heritable.

Wounded King responds to me:

quote:

---

OK, I understand that your argument was that we couldn't guage morphological and genetic data for a population of Gazelle in motion.

---

It goes deeper than that. The point I am making is that the ability to detect the distinctions among individuals depends upon how sensitive your instruments are. The reason that Newtonian physics lasted as long as it did was because our instruments weren't sensitive enough to detect the differences. What makes us think that we are capable of detecting every possible distinction?Plus, it isn't like the predators are consciously choosing which prey they are going to catch by taking an inventory of traits. Instead, they make an effort and if they are lucky, they catch the prey. Thus, it isn't like there is some specific direction in which the selection is applying its pressure.

quote:

---

Just because Syamsu doesn't understand any basic biology is no need to lower yourself to the same level of slapdash thinking.

---

Now that we have the ad hominem commentary out of the way, care to come up with a substantial argument?

quote:

---

quote:

---

Since there is variation, there is selection among the variants.
Hence, evolution.

---

​

Which obviously doesn't actually follow if the variation can be from non-heritable sources.

---

You're being disingenuous again.Is there a reason why you want to respond to the trivial rather than the substantive? As I said the last time you brought up this point: Care to respond to the substance of the post rather than trying to hammer an already conceded, trivial point?

quote:

---

If the point of the exercise is to show Syamsu that he is wrong the least we can do is try and be rigorous about it.

---

I know. Since I've already discussed the trivial case of there being no heritable variation and predation rates remain below birth rates, let it go and respond to the main point.

quote:

---

As to ignoring the feedback loop, obviously as I am saying a pre-requisite of this stable population is a predation rate equal to or below the replacement rate then why should I take into account a feedback loop based on a predation rate higher than the replacement rate.

---

Because it is an actual case: Population studies take a look at how quickly the prey is reproducing compared to how quickly they're being picked off. It is important, but it can only be extended so far. There are extenuating circumstances that will affect those numbers. There is more to what affects the number of prey available than simply how many got picked off. If there is an environmental crash that dramatically reduces prey, then that is going to have a dramatic effect on the number of predators, too, and whether or not their will even be predator and prey in the future. Similarly, there may be an environmental crash that reduces the number of predators.Thus, to simply look at just the predator as the only way to cull prey is a trivial case.

quote:

---

As to predators not eating everything, why shouldn't it be able to do that? If the prey outnumber the predators 10 to 1 I can't see the Lion chasing around killing 10 Gazelle Just for itself.

---

What makes you think a predator/prey ratio of 1:10 is going to be stable over time? You're thinking much too short term.

quote:

---

I can't find pretty much any of the things you claim to have said directly in any of your posts, did you say them prior to post 255?

---

They were the logical consequences of what I said.------------------
Rrhain
WWJD? JWRTFM!

It seems to me that there is a substantial difference between saying something directly and something being a logical consequence of what you said.I am intrigued that you consider your strange proof of evolution so trivial,in fact almost all the aspects other than those you failed to mention when first discussing this (Highly unstable environment) have now been dismissed as trivial, when they have been brought into question, so if they were so trivial why bring them up in the first place, why not just base your argument for the existence of variationon the varability of the environment? Because you were using an example and tried to fit it to your argument, I felt it was unsuccessful because of the many flawed assertions you were using to construct the argument.My substantive response was that since you have conceded that many of your initial premises are wrong, albeit in trivial ways, and to make your argument robust you have had to bring in some other factors. If you had put the case initially as you are now then I wouldn't have had any problem with it, but it is a significantly different case to the one you put to Syamsu.You post 255 was pretty clear in what it said, you made very specific points, some of which are rock solid I myself have said almost the exact same thing, minus the gazelles, to Syamsu on more than one occasion. This reasoning is almost the exact reverse of your previous specious reasoning that the existence of variation, of an unspecified type, proved evolution.Some of which, as I have pointed out, are rather more iffy Given the context I think it was reasonable to assume this was in reference to variation in the prey/predator leading to capture rather than variation in both populations allowing them to avoid variations in the environment, which is what you now seem to be claiming it meant.[This message has been edited by Wounded King, 08-05-2003]

Wounded King responds to me:

quote:

---

My substantive response was that since you have conceded that many of your initial premises are wrong

---

Incorrect. I do not concede them to be wrong. I concede them to be trivial. The difference is between those who wish to be disingenuous, harping on a single exception as if that destroys the entire viability of the argument, while ignoring the fact that we are not dealing with that trivial exception.In other words, we are dealing with genetic variation, not population studies. It is trivial to say that a single genome can produce non-identical individuals (for a variety of reasons) which allow the predator/prey relationship to remain stable so long as the cull rate does not exceed the replenishment rate.But surely Syamsu is not suggesting there is no such thing as genetic variation, is he? If so, then we have a whole lot more work to take care of before we can even begin to look at selection acting upon variation.Therefore, rather than harp upon a trivial example, we focus on the actual subject at hand: Selection upon genetic variation.

quote:

---

albeit in trivial ways

---

If you understand that the exceptions are trivial, then where is the claim that somehow something is wrong? Take the Fibonacci series. The nth term is calculated by adding the n-1th and n-2th terms.But what about the first two terms? They are missing at least one previous term.Indeed, but that's trivial. They are simply defined to be 1. That doesn't make the process of how to calculate the nth term "wrong" in any way. Yes, the 1st and 2nd terms don't get calculated by this rule, but so what? We have a method to determine what they are and those exceptions are finite and simply described. The fact that there are exceptions does not make the process wrong.

quote:

---

and to make your argument robust you have had to bring in some other factors.

---

Incorrect. We haven't even begun to discuss my argument. Instead, I've allowed myself to become bogged down in your disingenuous sidetrack. We're not talking about clones, are we? Surely Syamsu is not saying that there is no such thing as mutation, is he? If so, then we have a lot of work to do before we even begin to think about discussing selection.When I said, in my original post, that the gazelles are different, I wasn't referring to clones that experienced environmental factors that resulted in morphological differences. I was referring to the actual, genetic differences between the gazelles. Even if those differences are small, they still exist and thus, selection works upon them.Discussion about cloned individuals is a sidetrack.------------------
Rrhain
WWJD? JWRTFM!

quote:

---

When I said, in my original post, that the gazelles are different, I wasn't referring to clones that experienced environmental factors that resulted in morphological differences. I was referring to the actual, genetic differences between the gazelles. Even if those differences are small, they still exist and thus, selection works upon them.

---

I don't mean to nitpick but a lot of the variation is neutral and selection will not work upon it..it will drift to fixation or disappear by chance. The mitochondrial DNA reference for gazelles I posted is largely neutral mutation measures of genetic diversity...it is only surprising that there is so much among population diversity i.e. these guys have not gone through a genetic bottleneck and the populations are likely to be pretty old....now I will step back out and let you and Wounded King keep fighting

Well perhaps you should state your argument once again for us, I seem to have covered pretty much the whole of your post 255 so I don't see where I missed your argument out.The first section had your premise that "Since there is variation, there is selection among variants. Hence Evolution". Which is clearly not true. As you yourself pointed out there cannot be evolution without variation but there is no reason there could not be variation without, or at least entirely unconnected to, evolution.You then made a good point about Syamsu's abhorrence of any differential or comparison.You then seemed to accept Syamsu's twisted concept of Basic Biology for arguments sake and make a trivial point about thundering herds.You make another good point about how easy it is to study populations using good old fashioned concepts such as differential reproductive success as opposed to Syamsu's mutilated version.You then make your point, with which I heartily agree, that without variation there can be no evolution.It was the next bit of your argument that I took exception to. Obviously not the point that only those prey slow enough to be caught will be caught, that is undeniable. It was the bit about a 'no variation' population of predators and prey meaning that eventually there would be no prey slow enough for the predators to catch. This obviously completely ignores the fundamental premise that there is no variation! If there is no variation then there isn't going to be a distribution of fast and slow prey to be selected, they are all going to run at effectively the same speed. The idea that the predators are going to drive selection to faster running gazelles is fine, except that the whole point was that without variation there is nothing for selection to act upon!Your subsequent conclusion that the continued existence of predator/prey relationships proves the existence of variation does not stand up in and of itself. It does when you bring in environmental fluctuations having effects on the populations putting their relationship in disequilibrium, and show that they must be able to evolve to reach a new equilibrium (or fail to and go extinct), but that wasn't what you were arguing.I have made all of these points before and they address everything you said in that post, some in agreement some not, so where was the argument I failed to address?

Wounded King responds to me:

quote:

---

I don't see where I missed your argument out.

---

The part about the actual genetic variation.If you heartily agree that there can be no evolution without variation, why are you harping on a trivial case that I was not talking about in the first place?Does the word "strawman" mean nothing to you?------------------
Rrhain
WWJD? JWRTFM!

Oh!! So your argument was 'genetic variation exists!'. You certainly took a lot of extra words to say it.

I believe that this is the case with tortoise shell
cats (always female), and I suspect something of
this nature with blazes on the foreheads of
fancy rats -- very hard to breed for!!

If it isn't heritable it should be 'impossible' to breed for surely. But you are likely to have some due to chance.

You should work up on theory, on the fundamentals of science let alone biology. Generally selection is about continuation or not, like Brad McFall referenced. Yes you can apply selection to a single individual, you can even apply it to part of the life of an individual if you switch from looking at reproduction to looking at survival as the means of continuation. In science you are constructing knowledge, it's a technical task, you should make decisions about the fundamentals of the theory, and not keep with vague notions like you have. One or the other gets it. That is how you conceive of Natural Selection when you include variation in the definition.I wonder if in the computersimulations of Natural Selection there are actually comparisons calculated on the reproductive success of the different organisms. That seems SO COMPLETELY USELESS to calculate comparitive reproductive success. It seems to me you only need to program reproduction as a consequence of some interaction with the environment, and mutation to make a model of Natural Selection. I guess the standard theory of Natural Selection is not actually in the computermodel of Natural Selection, but only the cutdown theory.regards,
Mohammad Nor Syamsu

Syamsu,Please answer the question posed in this post. Why the reluctance? You seem so confident in your assertions, this should be a breeze.I believe forum guidelines pretty much demand a response.Mark------------------
Occam's razor is not for shaving with.[This message has been edited by mark24, 08-09-2003]

I have basically answered that question before in the same thread, you just changed the players/organisms.regards,
Mohammad Nor Syamsu

Syamsu, No, you didn't answer the question, they were subtly different (& you never answered them, either). The dog question was about which individuals were relatively fitter, the guppy question challenged you to explain colouration changes in a population without effectively mentioning relative fitness.You were asked to explain: Let me make it clearer for you, you claim to have "basically" answered the question. The question was to explain the colouration changes in the guppy population. You didn't do this, you therefore haven't answered the question, "basically", or otherwise.I don't care what definitions you use, I just want to know what is happening to allele frequencies over generations that allow all members of a population to be camouflaged when they previously weren't. In fact, don't use the word fitness at all, just describe what's going on & why. That way there is no confusion over definitions.Mark------------------
Occam's razor is not for shaving with.