March 21, 2011
A seemingly endless debate continues over the legitimacy of teaching evolutionary theory in classrooms, particularly in communities where religion plays a prominent role in community life. Some church leaders, teachers and school board members argue that alternate explanations provided by creationists or proponents of intelligent design should be taught alongside those of evolutionary theorists in science classrooms. People who are proponents of evolutionary theory are quick to offer a retort, usually suggesting that evolution is a proven fact; while denouncing the two aforementioned opposing views as belief systems which cannot be subjected to scientific analysis. Therefore, they suggest, such views are not appropriate subjects for science classrooms.
As too often occurs in such debates, each side is quick to dismiss the assertions of the other as fantasy, and imply that the sensible and reasonable person should not engage in non-productive contention with such headstrong opposition. When dismantling the arguments from each side, it becomes apparent that the most heated points of controversy often boil down to a matter of semantics. The scientific use of the term “theory” is quite different from the use of the word in general conversation. A scientific theory is a structured argument used to explain why things occur the way they do in the physical world, based on tested, measurable scientific evidence. A hypothesis, on the other hand, is an assertion about something (a speculative guess) that a scientist expects to be supported by future scientific finding.
Microevolution is a theory (as is almost everything in scientific study) which has been legitimately supported by laboratory analysis. Species can, and do, undergo genetic changes over generations which result in modifications of those species as. This has been observed and documented in laboratory experiments with fruit flies. As Northwest State College’s Jerry Bergman explained, “Some animals such as fruit flies live a very short period of time, enabling us to observe multi-thousands of their life generations. Even with a drastically higher artificial increase in the number of mutations, which are supposedly the source of variation which gives rise to the ‘stuff’ from which natural selection can select, no evidence exists that large changes have, or can, occur (Bergman, 1992, p. 3). In contrast to Bergman’s point of view, macroevolution suggests that processes similar to those observed in microevolution can, given enough time, result in the translation of one species into something entirely different (e.g. a reptile can evolve into a bird). There is no more scientific proof for the existence of macroevolution in nature than for the Biblical six-day creation story. Therefore macroevolution is nothing more than a hypothesis (ergo, a matter of faith).
Evolutionists are quick to assert that creationists and proponents of intelligent design are splitting hairs by accepting microevolution while rejecting macroevolution. However, the two concepts are vastly different. Francisco J. Ayala, of the University of California, Department of Genetics, wrote that macroevolution is “an autonomous field of study, independent of micro-evolutionary theory.” He further stated, “This claim for autonomy has been expressed as a ‘decoupling’ of macroevolution from microevolution, or as a rejection of the notion that micro-evolutionary mechanisms can be extrapolated to explain macro-evolutionary processes (Ayala, 1982, p. 279-280).
Ayala’s position supports the notion that microevolution is not contrary to creationism or intelligent design. No one disputes the fact that a myriad of possible breeds of canine can be derived from selective breeding of a vastly smaller number of common ancestors. However, the macro-evolutionary hypothesis alleges that, given enough time, the...