Can Domestic Selection cause Macroevolution?

The major aspects of evolution - at a simple level are:Variation : The appearance of new alleles or other genetic variations.Selection : The preferential spread (or elimination) od those variations that increase (or decrease) fitness.Drift : The chance spread of variatiosn which have little or no effect on fitnessIn terms of its effects from this perspective, domestic selection differs from natural selection only in that it is likely to be stronger. It is not going to have much effect on variation or drift, so it will only speed up evolution so much.From a scientific perspective, macroevolution could refer to phenotypic change in which case the array of variations in domestic breeds arguably meets. Darwin commented that the variation in sheep was such that paleontologists would identify some variatiosn as different species.If it refers to reproductive isolation (which is more likely to be the case with living species) then it is questionable whether domestic selection would make much difference. There's not much direct selection for it and I would expect it to usually be largely due to drift in many cases anyway.From a creationist persepctive, since known examples cannot easily be denied it is very unlikely that a creationist would identify any example as being anything other than microevolution.From the "across kinds" definition used by some creationists it is hard to see how any example would do. Eepcially since the usual definition of "kind" makes it logically impossible that evolution between kinds could happen anyway.From the "new information" definition used by some other creatioists, only new variations - or an accumulated set of new variations - could possibly do. And selection has no bearing on that. But given the vaguenss of the whole "information" concept used, it is unlikely that any example that we could reasonably expect to be observed would be accepted anyway. How can we say that a criterion has been met if we do not know what it is ?

Usually there is some factor to produce a split in a population, but I don't believe that even that is necessary. Can you explain more ?

"new information" is one creationist "defintin" of macroevolution. But they never give a workable measue of information so it's just another excuse to seperate the evolution they can accept from that that they will not.THe problem with defining macroevolution as speciation is that there are multiple definitions of species. The interbreeding criterion wrks reasonably well for extant sexually reproducing species but it's impossible to apply to extinct species. Therefore paleontologists go on morphology - or at least what they can find or infer from the fossils. I would suspect that the main limitation is missing "cryptic" species (tose that are morpholohgically idenital or nearly so, but don't interbreed).I'm pretty sure that the domestic varieties of the animals you list are gernerally considered a single species each. But it should be stressed that the degree of variation seen is a product of human selection and isn't at all typical of wild species, so it is unlikely to be an issue with ny wild animals.e

In allopatric speciation it is unlikely that there would be direct selection for infertility. Therefore I would tend to the view that drift is generally the most important factor.In sympatric speciation selection would almost certainly be needed for speciation to occur, but that is generally regarded as far less common than allopatric speciation.!

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This is what evos claim, but can you show me the peer-reviewed studies that compare mutational rates (remember studies of mutational rates exist) that are considered beneficial with rates of genetic decrease due to isolation processes envisioned with microevolution.

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As I pointed out to Faith when she introduced the idea, that is not a useful comparison. We only need neutral mutations to top up genetic diversity.

As I pointed out to Faith there is no evidence that there is a problem. Faith simply assumed that the rate of loss must exceed the rate of gain (without giving reasons). However there are theoretical reasons to doubt that (the rate of loss must decrease as the number of alleles decreases, and a dynamic equilibrium is the most likely position). Few wild species show a seriously depleted gene pool. Considering all changes at the genetic level neutral drift dominates over selection.And tying into speciation, the most rapid evolutionary change occurs when selection is relaxed. Small isolated populations are thought to be the usual source of new species not because of selection pressure but because genetic drift has a greater effect in small populations (and founder effects are relevant, too). This doesn't suggest that speciation has a particular problem with losing alleles through selection.Let me add that these points do not mean that selection is unimportant. It is very important, but its impact on genetic diversity is not so high as you seem to think.Domestic selection, involves intense selective pressure - while almost certainly relaxing pressures the wild population would be under. Taking domestic selection as a model without considering how it differs from natural selection in the wild is bound to be misleading, quantitatively and qualitatively.Now I don't know if there are any studies out there addressing precisely the point you want to look at. I don't even know if it would even be practical to produce one. It's up to you to explain what you want and then maybe we'll know.