Macroevolution
Macroevolution is a term used by Creationists to distinguish between what they perceive as different processes within the Theory of Evolution. However, scientists do not make this distinction, noting that the only difference between micro and macro evolution is the amount of time involved.
Macroevolution refers to the theory that natural selection can, given enough time, lead to the creation of new clades, which are groups of organisms consisting of a single common ancestor and all the descendants of that ancestor. While details of macroevolution are continuously studied by the scientific community, the overall theory behind macroevolution (i.e. common descent) has been overwhelmingly consistent with empirical data. Predictions of empirical data from the theory of common descent have been so consistent that biologists often refer to it as the on as the "fact of evolution".
Creationists accept that evolutionary change is possible within species ("microevolution"), but deny that one species can evolve into another ("macroevolution"). These arguments are rejected by mainstream science, which holds that there is ample evidence that macroevolution has occurred in the past.