A barrier to macroevolution & objections to it

There are any number of explanations. It could be that the weakened population suffers at the hand of a competitor by the time it starts to gain in numbers. Thus it cannot increase in numbers because as it grows in size more and more are killed, limiting their population size and thus making it difficult to increase diversity.Any number of ecosystem changes can reduce the maximum population size of a species which will automatically mean its diversity is stunted. Species which are nomadic by nature are thus doubly hampered because mates might be few and far between and (depending on habit) possibly fairly closely related.Just because genetic diversity can increase after a bottleneck doesn't mean it has to.

Come on Faith - you know better than this. Science never proves anything, and the ToE is not treated as fact.There is emperical evidence that mutations can increase diversity in organisms with very quick generational times - we simply don't have time to wait for several hundred generations of humans to go by in isolated conditions to show a new allele appearing. Instead we use reason - the same molecule is involved in bacteria as it is in humans and the basic same rules apply.So its reasonable that alleles can form from mutation.Finally there is no logical reason thatACG TCT GAA AAT GCCcouldn't mutate toACG TCC GAA AAT CGGwhich would be a new allele. What barrier exists that can prevent this from occurring? There is redundancy in the genome, and the language of DNA itself is redundant and it is physically possible to proceed one mutation at a time from one protein to any other. What can prevent this from happening? There is no barrier yet produced that would prevent this.The level of evidence you require is higher than a capital crime and with no reason.You say that mutation is assumed, but in cases where it is it is a scientific assumption (assuming mutations are the cause, we'd expect to see...oh look we do see).I could say that we are simply assuming that lightening is always electrical in nature just because we have a few small cases where we have measured it. There are thunderstorms going on all the time which aren't being tested and any one of those strikes could be some other force. Some kind of hyperrain or something.You might think you have some kind of reasoned argument, but eventually we need to actually look at the world around us and examine the things we are talking about. Mutation remains the best explanation because mutation has been shown to increase diversity in the lab. Mutation can be shown to be physically capable of increasing diversity and no force has ever been detected that will prevent this capability.

No - it's not, Faith. That ecosystems can change so that they can only support a smaller maximum population size of a species is a documented fact. You asked for an explanation, you were given one. You didn't give a specific scenario so you can hardly expect a specific response.

Agreed. Now do you agree that as long as the most likely possibility is that it's mutation, you can't just assert that it's pre-existing alleles instead? If you can design an experiment to allow us to observe 10,000 generations of a mammal lineage then we can do that. I don't know what the quickest turnaround that is possible but in rats from birth it takes about 4 months which I make the experiment will take about 3,000 years. Can you suggest a practical way to do this? The question is about barriers - at this time you have not demonstrated that an essential allele to diversity *cannot* be produced through mutation. You have demonstrated no barrier and there is no reason to assume there is one. Of course - and nobody has suggested otherwise. Most mutations to the coding region of the DNA either cause no functional change or the functional change to be a bad thing. But not all - so alleles can form from mutation that are not detrimental. So whatever barrier exists - this isn't the place to be looking for it. The thread isn't about beneficial mutations it's about a barrier that prevents macroevolution. We know that new allele's can be formed from mutation events, so you need to show where evidence of this barrier can be found. OK, let's try an thought experiment using the same random letters before: ACG TCT GAA AAT GCC
mutates to
ACG TCC GAA AAT CGGLet us say that the latter mutation has a slight detrimental effect on the survivability of the organism that has it. Fortunately, because of the redundant complexity in organisms other genes are able to pick up the slack so the mutation isn't fatal and the organism is capable of reproducing - just not as well as some of his competitors.Let's reverse things now. Let us now say that our population has some alleles. The best allele is
ACG TCC GAA AAT CGG. Since you are happy that the mutation can physically happen one way, it must be possible for it to happen the other way and have it mutate to
ACG TCT GAA AAT GCC. This allele is better than the first since it doesn't require help from redundant systems so everything works more efficiently increasing the fitness of the individual that has it.Agreed? Doubting the usefulness for evolution isn't what this thread is about. This thread is about a barrier to macroevolution, some thing that stops macroevolution. I have shown how a minor negative mutation could happen in reverse instead and be a positive mutation. I suggest that your time would be better arguing about new useful genes rather than alleles for existing genes since that is where any barrier to macroevolution should more logically be. Do you think that endangered animals and selectively bred animals represent a fair sampling when exploring whether or not genetic diversity increases over time? What about looking at animals that are flourishing - animals whose diversity is increasing as agreed on by biologists. Surely looking at selective breeding and animals which require conservation intervention is looking at a source that is only going to tell you about reduction in genetic diversity (by definition!!), regardless of the bigger picture. Then go ahead - biologists are doing the best they can, but it doesn't meet your standards. Nobody else on the creationist side has so far developed an experiment that could produce the level of evidence you require so I kind of figure that if it is possible, its unlikely. Since that is the case, the evidence you are asking for is of much higher standards than in a capital crime case. It would be like refusing to convict someone even when you have lots of evidence on the grounds that the jury weren't there. Except, of course, in all the examples where this hasn't happened that have been provided for you. To explain those you have to resort to some kind of hypergenome that contains all possible alleles that degrades even though you have no evidence of how this works, and no evidence of any of these hypergenomes even existing. They are a hypothetical unobserved entity. Your own standards of evidence should mean we should discount them until we find evidence of them, surely?There is no reason to think mutations can't be beneficial. Harmful mutations can happen in reverse, so a population that has the 'harmful' mutation exclusively and are still able to reproduce can have a mutation amongst them that puts it to the other state of affairs, which would be beneficial. New genes can form by duplication events and mutation acting on one gene whilst the other undergoes more mutation with no detriment occuring to the organism that has the duplication. So far, no barrier has been found or theorized that means these changes cannot be accumulative and lead to macroevolution.Sure - genetic diversity can decrease. Genetic diversity on earth is decreasing as we speak, the liberal hippies have been saying it for decades! There are animals which are recognized to be flourishing, whose population size is increasing not decreasing. If you want to falsify the proposal that their diversity is increasing, you (or some scientist with the same intent) have a lot of work cut out for you. If you want to show diversity decreasing in these higher animals it should be as straightforward as showing it in conserved animals and animals that are selectively bred.