Written for Mercury magazine.
Do you believe in creation or evolution? Take your time, because incorrect answers exacerbate the battle over teaching evolution in the school.
Creationists can truthfully answer that they believe in creation. But for those of us who practice or teach science, the correct answer is neither. That is, the question presents a false dichotomy. Religion is about beliefs, science is about evidence.
No scientific theory can ever be proven. A single piece of evidence contradicting a theory can, in extreme circumstances, cause the entire theory to crumble. But all the evidence in the world still does not constitute absolute proof. In terms of logic, scientific theories are built up inductively, so they can be evaluated only in terms of their strength, not in terms of their truth.
The distinction may appear to be mere semantics. After all, the theory of evolution stands on very solid ground. Besides explaining a huge amount of fossil evidence, we have seen evolution take place before our eyes. Bacteria adapt to antibiotics, HIV becomes resistant to new drug cocktails, and in a few cases, biologists have even seen local populations of animals or plants evolve in just a few decades in response to environmental pressures. Given all this evidence, it’s not surprising that scientists are tempted to say that they “believe” in evolution.
Nevertheless, I believe that more care with this semantic distinction could go a long way toward ending the conflict between fundamentalist religions and science. For example, I once had a roommate who was studying astrophysics but nevertheless believed Earth and the universe were created just 6,000 years ago. He reconciled his science and religion by envisioning a God who wants us to learn science so that we can use it to make the world a better place. In my friend’s view, God chose to help us develop science by deliberately making it look like Earth and the universe were much older than the actual 6,000 years. In essence, my friend agreed that the scientific evidence supports evolution but still chose to believe in creation. Scientifically minded people may object to the “convenience” of his explanation but we cannot prove him wrong.
The trouble is that us scientific folk have often talked as though we hold absolute truth rather than strong evidence. We tend to get worked up when someone says that evolution is “only a theory.” But it is a theory — albeit a theory backed by extremely strong evidence. If we want to lower the temperature of the debate over evolution in schools, we need to do a better job of explaining the difference between the domains of science and religion — namely, that science provides a predictive tool and a framework for explaining groups of observed facts, while religion deals with personal belief. Conflict should arise only when creationists try to claim that science supports their beliefs — in which case we must carefully present the evidence to the contrary. But I often wonder whether the whole issue of “creation science” was simply a reaction to scientists who presented their views too dogmatically.
So let’s start being more forthright in saying that the theory of evolution is a scientific model designed to explain many observations about the world. It’s a good model because it not only explains a lot but, like any good theory, it has predictive powers. We can use these predictive powers for human benefit. For example, we can predict how diseases will try to adapt to new drugs or how continued emission of greenhouse gases may alter the global ecology. Thus, it does not really matter what people believe about creation or evolution. What matters is that everyone should study evolution because it helps us understand our world.
Which brings me to the issue of the Big Bang. Like the theory of biological evolution, the Big Bang is a scientific model. Three strong lines of evidence support this model: (1) Hubble’s law, which tells astronomers that the universe is expanding; (2) the existence and characteristics of the cosmic microwave background, which tells us that the universe was once hot and dense; and (3) The cosmic abundances of the chemical elements, which agree with abundances predicted by the Big Bang theory.
Nevertheless, the case for the Big Bang is not as strong as the case for biological evolution and I believe we make a big mistake when we try to put both theories on the same footing. There are still many unknowns about the Big Bang, such as whether inflation really occurred or if/how a cosmological constant came to exist. It’s conceivable that, to scientists a century from now, our current view of the Big Bang will seem as simplistic as pre-Einstein interpretations of Maxwell’s equations seem to us. That is, the three lines of evidence will still exist, but may be explained in the context of a much broader theory.
Thus, while it’s a semantic mistake for a scientist to claim to believe in evolution, a claim of belief in the Big Bang could prove downright harmful. If the Big Bang is someday superseded by a different theory, we don’t want to be in a position where creationists can say, “See, you scientists never really know what you are talking about.” Because we do know what we’re talking about when it comes to scientific evidence; we just need to be careful that we don’t confuse evidence with truth.