A: Evolution stands on very secure ground. The hard data supporting it are numerous and varied. It is no less a satisfying and compelling explanation for the diversity of living things than is the notion of gravity for explaining the behavior of falling objects.

The statement, "After all, evolution is just a theory," is made frequently and causes lots of harm. The problem lies with the word theory - it means quite different things to different people. Most often the "just a theory" phrase is quoted in defense of the view that evolution need not be taken seriously because of the lack of evidence, that when all the facts are in it will be shown incorrect. Such arguments are based on the vernacular definition of the word theory, namely, a guess, an opinion, an unproven assumption, a mental speculation without a basis in the real world, a second class proposition near the bottom of the hierarchy between truth, at the top, and falsehood or fraud.

It is incorrect to view evolution in this way (1). The evidence is overwhelming that this earth is very old (in terms of human years) and that the life forms on the planet in their wonderful diversity are related by means of historical descent through time. The catalogue of facts supporting these conclusions is enormous. Contributions to the data which verify evolution have been made by thousands of men and women of integrity in a wide variety of fields of inquiry over many, many years. Our experience is that when diligent and open-minded students spend even a modest amount of time examining the data they become persuaded (and a useful measure for acceptance might be the legal standard of "beyond a reasonable doubt") that the basic evolutionary concept is valid.

To a scientist the word theory carries a very different meaning than it does in the vernacular. Yes, evolution is a theory, meaning a broad proposition based on facts and observations, which has undergone testing, which has stood the test of time, which best explains and gives meaning to the phenomena under study, and (true enough) is tentative (could be replaced if a more adequate, more valid explanation comes along). In what company does evolution travel - what other propositions with which we are acquainted also bear the title "theory"? Gravity, electricity, and atomic energy - to cite a few familiar examples - are also notions which have demonstrable consequences (are based on evidence), but are understood, explained and applied in practical circumstances because of theories. In short, if after scientific investigation an idea is granted the title "theory," this is high praise indeed. In this sense, if a person persists in undervaluing evolution as "only a theory," he or she, to be consistent, must also be willing to state, "After all, LDS theology is only a theory."

A scientific theory like evolution, then, is not to be distrusted as incorrect or inaccurate because it is open to modification. Scientific theory and religious theory are both true. By our commitment to the principle of continuous revelation, we acknowledge that our understanding of religious principles is also imperfect, and we must remain open-minded and receptive to new information. in the mature LDS investigator, both science and religion generate humility, as one recognizes the limitation of human understanding and continues to seek a clearer vision of the whole truth.