[Dante Alighieri]

Scientists are never absolutely certain. They may be highly certain however.

What of artificial selection? Speciation has been observed and the resultant species in many cases does not breed at all with the precursor species. Ergo, speciation, ergo, macroevolution.

[Oberon]

Look..."does not breed at all" doesn't mean "can't breed at all." If you can get past that point, you can't get the diversity of species we see in nature. At some point that line has to be crossed, or macro-evolution falls apart.

I'm willing to be agnostic on the matter, but to say that macroevolution is settled science is disingenuous.