It is not possible to get an accurate picture of evolution from creationist literature — creationists simply won't use key scientific terminology the same way scientists do. Because the subject is scientific, though, this means they are using key terminology incorrectly. What's more, it's implausible that they are ignorant of the fact that they are using that terminology incorrectly. So, it's difficult not to conclude that they are simply lying about science for the sake of a religious agenda.
One important topic where creationists consistently misrepresent evolution is in their attempts to separate microevolution from macroevolution. Creationists are unable to easily deny that microevolution occurs, but they need desperately to deny that macroevolution occurs. The only way to do this is pretend that they are fundamentally different processes. This, in turn, requires defining the terms in ways quite different from how real scientists define them.
Creationists' view of microevolution is similar to that of evolutionary biologists, but the two groups understand macroevolution very differently. Creationists accept microevolutionary processes affecting genetic variation of populations, and most also accept speciation, or the branching of a lineage into reproductively isolated groups.
But creationists take literally the evolutionary biologists' definition of macroevolution as "evolution above the species level," and infer that major groups of living things such as phyla and classes — the upper taxonomic levels characterized by body plan differences — have a qualitatively different history than lower levels such as populations and species.
They view the distinguishing features of phyla and classes as appearing suddenly, denying that such structures as segments, appendages, exoskeletons and the like could evolve through microevolutionary processes. Their definition of macroevolution thus overlaps only slightly with that of evolutionary biologists because they concentrate only on the emergence of new body plans or major features which distinguish "major kinds" of living things.
Effectively, macroevolution to creationists equates to the inference of common ancestry, which they reject. Their view is that because God created living things as separate "kinds," major groups and the features distinguishing them could not have come about through natural processes, microevolutionary or otherwise. Their position is "micro yes, macro no."Evolution vs. Creationism An Introduction, Eugenie C. Scott [emphasis added]
Reverend Harold Wallace, head pastor of a very large Southern Baptist church, Rollingbrooke Stones, in Atlanta, is a good example of how creationists view microevolution and macroevolution as being entirely different sorts of processes:
"No one, certainly not us Young Earth Creationists, or Creation-Scientists as we are sometimes called, is denying all change. We are quite happy to accept microevolution. Take something that you Darwinians are always pushing at us. Take those birds that Professor Davies mentioned, the Galapagos finches. There are ten or more different species of finch on the Galapagos Islands in the Pacific. We all accept that they came from a common ancestor.
It's just that the change is not from finch to tortoise or something like that. It's from finch to finch. We Creationists insist on some change. No one thinks that Noah's ark carried all of the species we have today. After they left the ark, the "kinds," as we call them, then diversified. It's macroevolution we deny." ...
"I have said before, I certainly believe that there has been a lot of change since Noah's Flood, and it would not surprise me to learn that much change occurred within the human species. This is all microevolution. What I deny is macroevolution. We brought up this distinction in an earlier program. A horse turning into a cow. A daisy into an oak tree. And above all, a monkey turning into a man."Evolution and Religion: A Dialogue, Michael Ruse [emphasis added]
You'll notice that Harold Wallace is unable to offer a single reason for why microevolution and macroevolution should be treated as distinct. He doesn't explain what logical or biological barriers there are between the two. The only "reason" comes at the end: above all, the belief that humans do not descend from other animals must be maintained. That is the length and the breadth of creationist approaches to evolution. Whatever maintains that belief is acceptable.
You'll notice that "kinds" is a key factor in Wallace's explanation of creationism. There is no consistent definition of "kind," except that humans are in a "kind" all by themselves. This is further evidence that maintaining a barrier between humanity and the rest of the animal kingdom is the driving force behind creationism:
Creationists often use the biblical concept of "kinds" to refer to those groups that were specially created...but within which some evolution is allowed. Explaining "kinds," one creationist website claims, "For example, there may be many species of doves, but they are all still doves. Therefore, doves would be a 'kind' of animal (bird, actually)." Thus, microevolution is allowed within "kinds," but macroevolution between kinds could not, and did not, occur. In other words, members of a kind have a common ancestor; members of different kinds do not.
The problem is that creationists give no criterion for identifying "kinds" (do they correspond to the biological genus? The family? Are all flies members of one kind, or of different kinds?), so we cannot judge what they see as the limits to evolutionary change.
But creationists all agree on one thing: Homo sapiens is a "kind" by itself, and therefore must have been created. Yet there is nothing in either the theory or data from evolution implying that evolutionary change could be limited: as far as we can see, macroevolution is simply microevolution extended over a long period of time.Why Evolution Is True, Jerry A. Coyne [emphasis added]
What creationists fail to understand — perhaps because they invest so much time and effort into misrepresenting and misunderstanding evolution — is that the acceptance of microevolution does not allow for continued denial of macroevolution:
In point of fact, the natural, evolutionary processes giving rise to adaptations are so well documented today that many creationists will tell you that they accept microevolution (adaptive evolution within a species) but that they do not accept macroevolution (evolution giving rise to new species).
However, by accepting the scientific explanation for microevolution, modern creationists, ignorant of the history of their own arguments, concede to the evolutionists the correctness of evolutionary explanations of adaptive, functional structures and processes by natural, unintelligent causes. Yet it was these very same functional structures and processes that were supposed to establish the need for intelligent causation as a consequence of the argument from design. ...
...the varieties that result from microevolutionary processes (processes driving changes within species that creationists have been forced to accept on pain of looking as silly as flat-Earth geographers) are driven still further apart by the continued action of the same mechanisms so as to constitute new species in their own right. In this way, microevolutionary changes, continued long enough, give rise to macroevolutionary phenomena.God, The Devil, And Darwin: A Critique Of Intelligent Design Theory, Niall Shanks [emphasis added]
Once creationists accept that natural selection, mutation, genetic drift, and gene flow are real processes that drive microevolution, they necessarily accept that those processes exist and operate in nature. They are unable, then, to deny that such processes can lead to the development of individuals unable to mate and produce fertile offspring with earlier ancestors (if they were able to meet). Thus the acceptance of the reality of these processes means the acceptance of macroevolution, speciation, and ultimately common descent of all life.
