While we are able to see microevolutionary changes within a single lifetime, visual observance of macroevolutionary changes is not possible.
that's nice. what's microevolution? what's macroevolution?
i make no distinctions, personally. evolution is evolution and i see no glass ceiling preventing changes from compiling. but since you do, please define spefically what you are looking for. where is the line between the two kinds of evolution?
this question must be addressed, and it must be addressed first, before we get to what mechanism would stop further change, or what reason changes would not compile.
I have seen nothing to date that would convince me that macroevolution is not a myth. One analogy that I can give would be the christian myth of noah's ark. Were we to actually find this ark, this would still not be concrete evidence of the story as told in the blble. We may have the visual evidence that the ark actually existed but this would not be enough to confirm the biblical account of noah and the ark beyond any and all reasonable doubt.
if we had a nice steele on the site of a giant boat exactly matching the descriptions in genesis that said "here i, noah, sacrificed to the LORD god in thanks for saving my butt from a big flood that killed everything else." it might help. or if the other people who were alive at the time actually had died off.
evidence is not proof of textual correctness. in bible class, we looked a babylonian inscription once that heralded the victories of a king over a league of foriegn nations, including israel. but the inscriptions start going backwards, and the "victories" start become less and less magnificent. even though the record itself SAYS this king won all these battles, the inscriptions SHOW that he did not. it's like if 2000 years from now, archaeologists would find a bunch of magazines that say "america is doing great in iraq!"
Would their belief, their willingness to suffer what they suffered be enough to convince you of the reality of their god? I doubt it, but they believed and were willing to die proclaiming that belief.
well, it took about 200 years before they convinced one very powerful roman, and the rest, as they say, is history.
Somehow I doubt any that macroevolutionist will ever have that level of commitment to their own beliefs. I am quite sure that they would be willing to deny their belief in macroevolution and do it in a New York minute. There is a drastic difference between someone who simply accepts something and someone who not only believes but is willing to remain faithful to that belief even under penalty of torture and death.
evolution is not a religion. it's not a die-hard conviction. it's not a belief. and if they don't have that level of commitment, it's because they know that further tests could yield new data, and modify the theory. overturning is very unlikely, as it has FAR too much data supporting it. but as i said, if you can show that some mechanism exists that keeps 1+1 from equalling 2, then you're all set.
even if intelligent design is true, it does not disprove evolution. the existance of a concious hand in our creation does not stop evolution from happening and modifying that creation.