How do you solve a problem like Moran? Prof talks about problems in talking evolution
Vincent Atienza
Last Wednesday, the Guelph Skeptics hosted a talk by Dr. Larry Moran, a University of Toronto professor, entitled "Evolution as a Fact and Theory." He aimed to address the misconceptions that people have about evolution such as that humans are not descended from monkeys; we just had a common ancestor.
These misconceptions have created the evolution controversy in the US and a bigger divide between science and religion. He points out that a lot of it can be attributed to misunderstandings of scientific concepts that even some members of academia can be confused by.
According to Dr. Moran, the minimalist definition of evolution would be, "a process that results in heritable changes in a population spread over many later generations." He emphasizes that it is heritable changes in a population not in individuals. So a human possessing claws coming out of his hands and the senses of a rabid animal does not count as evolution.
Along these same lines, a trend of increasing height in a group of people does not count as evolution. Dr. Moran used the example of the short armour height of medieval Europeans to explain that the Europeans' taller, present-day height is not evolution because there was no genetic change involved. That is, they need a structural change in their DNA, the recipe for life.
In actuality, increased height was attributed to the improved diet of Europeans and not to a change in their DNA structure.
So what counts as evolution? It usually occurs when a population, which is a group of interbreeding individuals, splits up because some individuals are not able to interbreed with others (sadly being rejected by someone at Trapper's does not mean you're evolving).
Changes between the groups accumulate over time and eventually new species are formed. Dr. Moran used the pests of park benches everywhere, the Canada goose, as an example to illustrate that point.
There are two main species of Canada geese, Atlantic Canada geese (Branta canadensis) and the smaller Cackling geese (B. hutchinsii). They have very similar features and were once considered different "races" of Canada geese. It wasn't until July 2004 that the American Ornithologists' Union considered them as two separate species.
The talk was also meant to alleviate any misconceptions of scientific method that even some science students have trouble grasping. It concerned itself mainly with the definitions of fact and theory.
As boring as definitions sound, understanding them is important because a lot of anti-evolutionary arguments use incorrect definitions of these words. In everyday language, hypothesis, theory, fact, and law imply a degree of certainty from lowest to highest. This is not the case in scientific terms since they are all used in different contexts.
Facts are any observation that has been repeatedly confirmed and considered "true" by the scientific community. According to a journal article by U of G evolutionary biologist, Dr. T. Ryan Gregory, "small-scale details are regularly revised as more precise observations are made" and "facts of fundamental significance are very rarely overthrown."
Observations can range from seeing changes in the fossil record to the Canada geese example from above. Small modifications to evolutionary facts, such as which terrestrial ancestor gave rise to whales, can be changed, but it does not change the fact that evolution is still occurring and species are still changing.
Whereas facts are similar in both their common and scientific meanings, theory is a little bit trickier. The word "theory" is usually used similarly to the word "guess," but scientists use a more concrete definition of theory. Theories are "the ultimate goal in science"since they seek to propose mechanisms that explain facts.
Any crackpot can propose a mechanism. The most important part of a theory is that it must be testable, or otherwise it is not valid. Many theories have been proposed and dumped, like a bad date, by many scientists because they do not agree with established concepts.
The Lamarckian theory of evolution, for example, proposed that traits were passed on by use and disuse. This view is incorrect because it does not agree with modern genetics and it implies that evolution fulfills needs and has foresight (which it certainly does not or else we'd all have wings and four arms).
The best theories are those that can account for the most observations and make the most accurate predictions. Modern evolutionary theory consists of mechanisms that account for changes due to non-random (via natural selection) or random (via genetic drift) factors.
There is debate within scientific the community between mechanisms of natural selection and genetic drift, but it is about which is more frequent; not whether evolution is occurring or not.
At the end of the talk there was a question and answer period, which was spent mostly addressing problems that some people had with evolution. It did not turn into a shouting match between creationists and scientists, like at The Conflict event in October 2007. Dr. Moran addressed the concerns of each person politely and without incident.
To access a free version of Dr. Gregory's article, "Evolution as Fact, Theory, and Path," visit: http://genomicron.blogspot.com/2007/11/evolution-as-fact-theory-and-path.html
