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 "fact of evolution".[5][6] Nevertheless, macroevolution is sometimes disputed by religious groups. Generally speaking, these groups attempt to differentiate between microevolution and macroevolution, asserting various hypotheses which are considered to have no scientific basis by any mainstream scientific organization, including the American Association for the Advancement of Science[7].
When discussing the topic, creationists use "strategically elastic" definitions of micro- and macroevolution.[1] Macroevolution, by their definition, cannot be attained. Any observed evolutionary change is described by them as being "just microevolution".[1]