The dilution of the effects of genetic mutation.

"Diluted" is not the right word.A (diploid) organism will have 0, 1 or 2 copies of a given allele.When a new mutation arises, you have one member of the gene pool with one copy.Now this can't be "diluted", as such, because the only whole number smaller than 1 is 0.Of course, it can fall to 0. Even if the mutation is a very good one, a tree could fall on its carrier or something, C'est la vie. That depends ... I have seen it said that when the rat poison warfarin was introduced, similar mutations against it emerged and then were selected for in different places. And, since mutations are random, we may presume that such mutations had been cropping up in rats since first there were rats, but were never selected for because there wasn't any warfarin.Of course with rats you have a large geographically widespread species. In a smaller population in a smaller area, it would be more likely that a successful mutation would start in one individual and spread through the population before it could occur a second time. I'm not quite sure what you're getting at --- if by "an incompatible feature", you mean something that makes the net effect of the mutation harmful, then (except by some wild fluke) it would be eliminated by selection. Well, it wouldn't be selected for at all unless there was malaria where you live.So suppose there is. But this still leaves an element of chance, because there are lots of other things that can kill you and your offspring. There's always this element of chance --- it's called genetic drift --- it's natural selection's idiot kid brother. A mutation is particularly vulnerable to this, of course, when it has only a few carriers, as in the scenario you describe.In fact, if you do the math, most beneficial mutations will go extinct in the population despite their benefits. So it's a good thing that there are plenty of them (genes for warfarin resistance in rats, for example, must have been produced by mutation more often than they succeeded in spreading through the gene pool). Well, hooves aren't an all-or-nothing feature, as you can see by studying the well-documented evolution of the horse. The central toe got bigger, the outer toes became smaller, then vestigial, then vanished.I don't quite see how this fits with your other questions.---P.S: Welcome to the forum.Edited by Dr Adequate, : No reason given.

You seem to be missing a few points.One mutation doesn't make a new species. Or if it ever did, then that new species would start off consisting of one individual unable to mate with the old species (by definition of species) so it would be an evolutionary dead end.Rather, what turns one species into another is an accumulation of changes over generations.Here's an analogy: I speak the same language as my parents, who speak the same language as their parents, who spoke the same language as their parents, and so forth. And yet if you go a thousand years back you find that my ancestors spoke Anglo-Saxon, which looks like this: (If I tell you that this is the Lord's Prayer, and that and are how they wrote "th", then you may see some relationships with Modern English.)Now, this is a different language from Modern English. And yet there was never a point at which one person started speaking a brand new language, comprehensible only to his children whom he raised speaking this new language. At every point, people's language was comprehensible to their neighbors, their parents, their children ... and yet by progressive small changes, we ended up with a different language.The normal process of speciation is like that. It doesn't happen by one big jump producing incompatibility.Edited by Dr Adequate, : No reason given.Edited by Dr Adequate, : No reason given.

This is slightly misleading, because it suggests a situation where all the genetic material for a new species is present in one generation just waiting for recombination to assemble it into a new species. Which is not what happens.

No, not necessarily. Even assuming, as you do, that there was a sudden leap from non-striped to striped, it is arguable that if you have a bunch of equids, only one of which is striped, dashing about in front of a bunch of lions which are also dashing about, then the striped zebra would be more visually confusing ... especially to lions who have not evolved to hunt striped zebras, and whose instincts are attuned to hunting zebras that are pure blocks of color.