There exists in this world people who refute evolution on the basis of a rudimentary definition. They are creationists. To them, theory stands anathema to fact. By this view, fact describes an occurance while theory is conjecture. This is not only a simplification; it's just wrong. Theory is comprised of facts. It is a modeling tool.
Since a framework is not a fact, creationists attack the Theory of Evolution as implausible. And since one conjecture is worth another, they propose in its place an alternative argument. This contention is a misnomer. Evolution is a fact; natural selection is a theory.
As I write this, a certain English bulldog demands my attention. Few animals can better illustrate the fact that is evolution. Bulldogs were non-existent just four hundred years ago. Their steady progression from Pugnace to extra cute is well documented. Evolution describes changing genetic frequencies over generations. My dog is the manifestation of such changes. To deny evolution is to deny the existence of my dog.
Theory attempts to explain the mechanism by which evolution occured. For theory to be plausible, it must explain all facts. As contemporary humans disappear from the fossilic record, archaic ones become more prevelent. At some point the genus homo vanishes from the record. So, too, does the class Mammalia. A plausible theory must explain these facts.
Languages change; they appear and vanish. They borrow from one another. Most importantly, they tend to branch like a tree. Linguistic adaptions occur at various rates dependent upon a variety of factors. A plausible model of human origin must account for language distribution.
By virtue of thumbs and a comparatively larger brain, members of the genus homo were inclined to use tools and later to create technologies. As a result, they were able to expand their inhabitable zone. Tools and technologies are an essential component of the essense of Homos Ergaster and Neaderthalis. Homo Sapien leveraged them to dominate the earth. A model of human origin must account for this very important trait.
Such changes manifest themselves in time. Tools first appeared around 1.4 million years ago. Language, as we know it, probably appeared during the "Symbolic Explosion" in the Upper Paleolithic. A plausible model must include dates of these events, the peopling of individual continents, dates in the fossilic record, predictable changes in mitochondrial DNA, along with a ton of other data.
Natural Selection is the current working theory which best explains speciation through the mechanisms of evolution. Evolutionary Origins is usually applied to a single species or a single trait. It is current framework with which we explain the origins of Homo Sapien. Creationists may certainly offer an alternative framework, but as long as they continue to arbitrarily select facts to fit their model, then it will continue to remain implausible.
