the phylogeographic challenge to creationism

Mick, Great post!Mark

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There are 10 kinds of people in this world; those that understand binary, & those that don't

Faith, How could you, one of those processes does nothing but increase genetic diversity, & it happens with every individual with every generation.Mark

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There are 10 kinds of people in this world; those that understand binary, & those that don't

Faith, A topic of its own, but its neither here nor there, here. The point is you have no reason to claim NS reducing diversity is a block to evolution when mutation introduces it all the time.Mark

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There are 10 kinds of people in this world; those that understand binary, & those that don't

Faith, My answer is the same, you have no reason to claim NS reducing diversity is a block to evolution when mutation introduces it all the time.If a mutation introduces a deleterious or neutral genotype, then diversity still increases. Increasing diversity via mutation cannot be argued. It happens in every individual in every generation. Most of them are neutral, but no matter. This highlights the real shift in your argument. You are no longer talking about decreasing diversity, but the old chestnut, "there aren't any/enough beneficial mutations".Mark

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There are 10 kinds of people in this world; those that understand binary, & those that don't

Faith, No, it is meaningless to speak of genetic diversity representing a block to evolution. More genetic diversity does not necessarily mean more beneficial mutations.Time to call a spade a spade, Faith. Your issue is not with diversity, but beneficial mutations.Mark

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There are 10 kinds of people in this world; those that understand binary, & those that don't

Faith, You keep stating this like you are scoring a point. What is that point?Mark

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There are 10 kinds of people in this world; those that understand binary, & those that don't

Faith, It's falsified if you can show that mutation isn't an effective counter. This requires evidence. But then at the time that the population levels are crashing it probably isn't a counter, only afterwards.Hall (Hall 1982) removed the ability for a single bacteria to metabolise lactose. He removed the genes that coded for the enzyme, the permease, & the expression control. As far as your scenario is concerned the situation could not reduce the populations diversity more, it was first reduced to a single organism, then even more was removed. All three functions re-evolved in the susequent grown culture.

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Thus an entire system of lactose utilization had evolved, consisting of changes in enzyme structure enabling hydrolysis of the substrate; alteration of a regulatory gene so that the enzyme can be synthesized in response to the substrate; and the evolution of an enzyme reaction that induces the permease needed for the entry of the substrate. One could not wish for a batter demonstration of the neoDarwinian principle that mutation and natural selection in concert are the source of complex adaptations. [DJ Futumya, Evolution, ©1986, Sinauer Associates, Sunderland, MA. pp. 477-478.]

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In other words, reduction of diversity to a single individual did not prevent evolution.MarkThis message has been edited by mark24, 12-07-2005 06:42 AM

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There are 10 kinds of people in this world; those that understand binary, & those that don't

Faith, It has been tested, reducing a populations diversity to a single individual didn't prevent evolution. Again, the point of my post seems to have escaped your notice. A gene pool with the minimum diversity of one individual didn't prevent evolution. The maths are irrelevant. Genetic changes occurred, therefore mutation occurred. It was mutation, there is no evidence of preordained change. The vast majority of the bacteria died when only sucrose was available as food. Don't be obtuse. It quite obviously demonstrates that evolution occurred in spite of minimum diversity. There is no evidence of anything other than common or garden mutation being at work. If it were something else, then we would expect all bacteria to get the same preordained corrective mutations. They didn't. Of the billions/trillions of individuals involved almost all died when the cultures were transferred to an all sucrose substrate. Exactly what we would expect of a random process, & exactly the opposite of what we would expect if the proccess were "in built".In any case, this is ad hoc speculation on your part. Whichever way you look at it, diversity recovered from an absolute minimum. This falsifies your stance that diversity reduction prevents evolution.Mark

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There are 10 kinds of people in this world; those that understand binary, & those that don't

Faith, Please tell me how it is possible to reduce diversity further than bringing the population down to a single individual, & then removing genes from it? Yet diversity still increased. Yes, you did. Your argument that reduction of genetic diversity is a barrier that prevents evolution. Hall reduced a population to a single individual. You cannot decrease diversity more than that. Evolution still occurred. What brings them to a brick wall? Diversity increases again or it doesn't. We know it does so it's hard to see what your arguing against.I deliberately chose an asexual reproducer because several things reevolved in a single lineage. With sexually reproducing organisms it's even easier for us, you can get three things in three lineages that all end up in the same individual because genes get shuffled & introduced to other alleles during sex reproduction in general. No, it isn't, it was an example that was sufficient to counter your claims. From minimum diversity, diversity increased. Evolution occurred, ergo loss of diversity doesn't represent a show stopping barrier to evolution.The original paragraph I took issue with was the following: Not only does the evidence not support you, it directly demonstrates that your position is wrong. Mutation is a sufficiently effective counter to diversity loss.MarkThis message has been edited by mark24, 12-07-2005 04:35 PM

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There are 10 kinds of people in this world; those that understand binary, & those that don't

Faith, I believe the phrase, "none so blind..." is relevant here. You did make your case, completely evidence free, I might add, & all it took was one lousy vague experiment to shoot you down in flames. It's the difference between wanting something to be true, & demonstrating the truth. Hold that thought. First point, one unreplicated test still demonstrates your position is false.Second, in fact this experiment has in essence been repeated over & over in schools, colleges, & universities all over the world. You can even do it in your own home. All you need is a load of petri dishes, agar jelly impregnated with sucrose & lactose, plus some lac- E.coli. But it's easier to shut your eyes & stick your fingers in your ears rather than accept you are uttlerly, utterly, wrong, isn't it?Mark

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There are 10 kinds of people in this world; those that understand binary, & those that don't