Not confusing - replacing. The mutation “rate” makes sense after you’ve already bought into the notion that the starting point was at a certain other point. Once this is accepted, you can calculate the rate of change required to bring from Point A to Point B. But if that is itself what you are trying to prove (i.e. common descent), you can’t just accept that there is a rate - that would be circular. I pointed this out a couple of posts back - perhaps you missed it.
Your horse and rhino detail seems in line with my summation in my previous post. If you were trying to say something else, I’ve missed it.
OK. So considering only coding DNA, birds are not more similar to alligators - you meant genetically similar in terms of pseudogenes. This was not originally clear.
Not really. Mutations can clearly take place. (Bacteria would be a good example, in reponse to modern antibiotics).
I was merely saying that if you are going to claim that pseudogenes’ rate of mutation is in accordance with evolution for functionless material, this should have a consequence should they turn out to have a function. Otherwise it is a non-falsifiable statement.
But I gather you are now saying that if it turns out to have a function, it will turn out to be one that is not affected by mutations. OK.
One question along these lines. In these days of genetic technology, why doesn’t someone just do some experiments with removing or altering all the psudogenes and see what happens?
A moment’s thought should disavow you of this notion: consider the differences between a caterpillar and a butterfly. Both are genetically the same individual, yet morphologically very different. A lot happens during development which can have profound effects on the final morphology of an organism. While ultimately these developmental effects may be under genetic control, one cannot determine anatomy directly from the genome. There’s a lot that happens betwen genome and ultimate morphology that isn’t fully understood.
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This is not necessarily so - it depends on which reptiles you wish to compare birds to. Compared to crocodilians, birds have many anatomical similarities; indeed, crocs are the closest living relatives of birds (assuming one accepts common descent - if one does not, then one must simply acknowledge that among living creatures, birds are most similar to crocodilians). The anatomical similarities between birds and crocs are much greater than are the similarities between either group and mammals.
I am confused as to why pseudogenes and their function or lack thereof has any significance to creationism vs evolutionary models.
Certainly pseudogenes are useful as part of an evolutionary model. Their presence is consistent with a model that proposes that retrotransposons copy and reinsert genes in toto and that as those extra copies of genes get copied through the years and accumulate mutations, one of two things occur: they acquire some added value (novel function) to the organism and organisms with that modified version are selected for; or they do not add any extra selection value and those copies that are shut down by stop codons are selected for, since that means less wasted resources spent on production of excess gene product.
Could pseudogenes still provide some other function than that of gene product? Some chromosomal structural function or such? Maybe. And that would support creationism how?
On the other hand, one could really only say that pseudogenes supported evolutionary theory (rather than helped to provide explanations of the mechanisms of) if the theory had predicted their discovery ahead of time. Was this the case?
Well, my point WRT pseudogenes is that they support evolution in that evolution lets you explain pseudogenes in a fashion which makes testable predictions, which have been borne out. OTOH creationism can provide no such explanations.
To draw an analogy, the space program supports helicentrism (or, more directly, Newton’s explanation of heliocentrism using the “atheistic” theory of gravitation- and yes, people called it that.)
How so? Because using the theory of universal gravitation, you can calculate the course of a space probe. When you actually send out the probe, it goes where you predicted it would. If the theory of universal gravitation weren’t true (if, for example, planets were mounted on crystalline spheres, or were moved by angels) then something else would happen.
According to IzzyR’s logic, then that’s circular logic. When you devise the test, you’re making predictions based in the framework of the theory of gravitation. When those predictions are borne out, well, HA! of course it’s going to say gravitation is right- that’s the assumption you started with.
IzzyR, under what circumstances would you not consider the scientific method to be circular logic?
I don’t consider your proof to be circular in the form that I put is a couple of posts back. I brought in the circular logic in reference to your insistence that you could assume a “mutation rate” while in the course of proving evolution. To which my response was that the mutation rate only exists after you assume evolution.
In your analogy, it would be as if we don’t have universal agreement that the probe went where we predicted, and that this in itself was part of the theory.
So I think you can claim that the observed number of differences is consistent with the theory that these represent a relatively constant mutation rate. But you cannot just ask creationists to explain the mutation rate - they don’t agree that what you are describing is a mutation rate.
The thought occurs to me that the mutation rates should express themselves in terms of the number of generations that have passed, not the number of years. This because each new generation represents one chance at a new mutation, not each passing year. So that if the mutation rate was a constant, you would expect to have far more mutations in the same amount of time in mice as compared to elephants.
But this should make it difficult to calculate a standard rate, as the number of generations that a creature passes through as it changes from one species to another will be unknown. So that, for example, if mice and elephants sprang from a common ancestor, that ancestral mouse/elephant would presumably have had an average generational duration at some point not the same as current mice or elephants, and the situation now would itself be a product of evolution. Exactly how fast this change took place would be highly speculative, which would seem to undermine our ability to determine how many generations have taken place since that time for each species.
Also, as we’ve discussed previously, it would appear that the universal distribution of a pseudogene mutation within a species can be accomplished only by genetic drift - i.e. random chance. This, in turn, is heavily affected by population size, making a prediction about the likely rate of accumulation of pseudogene mutations a function of an assumption about the population size at all points of the evolutionary development - but particularly at the time of the mutation. It’s hard to imagine how this assumption might have been come by.
In light of the above, I’m curious as to just how it is that evolutionists can calculate a mutation rate at all.
Actually, it’s each cell division that represents a chance to incur one (or more) mutations, not each generation. A species that takes a long time to reproduce (such as humans) may have the genes in its germ-line go through more cell divisions than a species that takes a short time to reproduce. I mean, come on, how many sperm does a human male manufacture in his lifetime? And each sperm is the product of meiosis from a germ line cell which itself may have gone through several “generations” of mitosis to get there.
Some more clarification here would be appreciated. It apears that you are saying that on the way from sperm (or egg) production to birth there might be a different number of cell divisions for different species - each representing one chance at a mutation. If this is not your intention, please correct.
In any event, do you have any evidence that the number of cell divisions is directly inversely correlated with average age at reproduction? If you don’t, it would seem that you are introducing yet another variable, making the calculation of a mutation rate still harder.