Teaching Evolution Is Not Vital?
Dirk Van Tuerehout, PhD, responds to a recent comment about the lecture "Teaching Evolution Is Vital" given by Dr. David Hillis in April 2008. Comments on our blog entries are always welcome.
Mr. Zimmerman makes the point that there is a "great lack of scientific consensus among evolutionists regarding the entire field of evolutionary thought." He also refers us to the entry on evolution at the Conservapedia website. I would like to react first to the statement and then share some thoughts on the Conservapedia writeup on evolution.
The theory of evolution is subject to questioning on a daily basis. This is done by scientists working in fields as far apart as medicine and paleoanthropology. Because of this, I would argue that the statement made above oversimplifies the nature of the questions being asked by interpreting this as a lack of consensus. It is not.
Every new discovery made in the world of living organisms or in the realm of fossilized remains of now extinct life inevitably leads to questions as to how this new find fits within the theoretical framework of evolution. It is important to realize two things that happen when this questioning occurs: if a discovery leads us to conclude that we need to re-think evolution, then we ought to do so; also, while scientists do ask questions and do make changes to our understanding of how evolution works (think punctuated equilibrium vs. gradualism), there is no disagreement among scientists that evolution is actually and factually happening. In other words, the discussion pertains to the ways in which evolution operates, not whether or not it exists.
In my opinion, this is the (often unstated) crux of the debate between the two sides: proponents of Intelligent Design and Creationism imply the scientific world is in disarray, the proponents of evolution fail to make the point often enough that the "squabbling" is about modalities, not the actual existence of evolution itself.
Another criticism leveled against evolution is that, while microevolution might be acceptable, macroevolution (i.e. the evolution of separate species) is not. Most often this line of thinking is reflected in writings critical of evolution along the lines of "did we ever find the fish-dog fossil?" Since the answer is no, the implication is that in that case we cannot accept evolution.
I would argue to the contrary. The notion of fish dog creatures is an oversimplification. There are fossils showcasing how marine life forms evolved traits that (pre-)adapted them to life on land. There are also good explanations offered as to what evolutionary pressures might have made such adaptations beneficial for survival, ultimately leading to land based life forms. In this context, I strongly recommend that Mr. Zimmerman reads the recently published "Your Inner Fish" by Dr. Neil Shubin. The author writes in very easy to follow prose how he and his colleagues formulated a research question and then set out to collect the answers. They did find answers, in the form of very ancient fish fossils. What I particularly liked is the link Dr. Shubin makes between these 375 million year old fossils and us, and how we share a number of traits with these ancient life forms. I am very aware that this book was dismissed outright by those critical of evolution. As Dr. Shubin addresses these concerns in his book, I can only recommend that Mr. Zimmerman reads this for himself, and then makes up his own mind.
With regard to the entry on Conservapedia, one will find a very wide array of criticisms against evolution. Most of these have either been debunked or else are far from scientifically relevant. Let me give a few examples.
1. Reference to Ernst Haeckl
Under the header "evolutionary theory and cases of fraud, hoaxes and speculation" there is condemnation of the work of Ernst Haeckel. His now famous depiction of embryos and his contention that these embryos reflect the various stages evolution went through were, indeed, at one point considered to be part of our scientific understanding of evolution. The emphasis here should be on "at one point." It was true a century ago, it no longer is.
Scientists have gained much better insight and have come to the conclusion that Haeckel was wrong. The contention that we still find reference to Haeckel in modern textbooks is misleading. Yes we still find references to Haeckel's embryos, but only to illustrate the history of the field, not to illustrate contemporary acceptance of his thinking. An analogy to this would be to open a geography text book and attack the notion of a flat earth discussed in an introductory chapter, where the history of the field is discussed. This notion is equally dismissed today.
We are separated by a century from Haeckel and his research. We have made great progress in technology allowing us to probe and look for answers where Haeckel could not and did not. To imply continued acceptance of Haeckel's ideas by the contemporary scientific community reflects at best a lack of insight into the history of the field and at worst a willful disregard of this information to promote a non-scientific agenda.
2. Linking Darwin and evolution to Hitler.
As one scrolls down the Conservapedia text, one finds the header "Social effects of the theory of evolution." A photograph of Hitler and quotes associated with this header make it abundantly clear that the author(s) link Darwin to Hitler and therefore very strongly suggest one ought to reject both the individual and his writings. I deplore this kind of over the top reasoning. It is the equivalent of tossing a nuclear bomb into a conversation, aimed at ending it rather than promoting an exchange of ideas which is often the stated goal.
This kind of tactic has a name; it is known as Godwin's law. It states "As a Usenet discussion grows longer, the probability of a comparison involving Nazis or Hitler approaches one." In other words, once this comparison is made, the conversation is over. It should not be. Neither side ought to be afraid of engaging in a respectful exchange of ideas. It is only through this constant back and forth that we can better formulate ideas, and abandon bad ones.
I would like to end by re-stating that it is indeed important to teach evolution and to share with people that scientists question the notion of evolution on a daily basis. Evolution is not carved into stone, immutable so to speak. Quite the contrary, just like life it aims to explain, the concept of evolution is a vibrant one and it is better understood by all of us as research continues.
