“But evolution is just a theory!” A common argument heard all too often from staunch opponents of Evolutionary Theory. However, evolution is the fundamental theory essential to modern-day biology – without it, our biological understanding of the world crumbles. So if the entirety of our understanding about biology rests on the back of a “theory”, how can we be sure that we know much about biology at all?
Just a theory; Just a theory… If you want to make a biologist cringe, tell him or her that evolution is just a theory. Yet, if you told a random stranger on the street that evolution is ‘just a theory’, they would probably agree with you and disregard its validity. This suggests that the definition of “theory” means something much different to a biologist than it does to a non-biologist. But “theory”, at least in ecology, really only has has a single definition; so why the discrepancy? The answer inherently lies in the interpretation of “proof”.
In science, with the exception of mathematical proofs, nothing can be “proven”. That is, 100% proof of something cannot be obtained. This is because science works on the principle of disproving prior ideas. As ideas are tested, and are failed to be disproved, they gain more and more evidential support for their existence and truth. Once enough evidence supporting the reality of an idea surmounts, that idea becomes a theory. As science continues to test a theory and continues to fail disproving it…it stays a theory. But why? If so much evidence supports a theory, why does it never become a fact? This is because there is always a chance that even the most well supported theories could be disproved. As unlikely as it may be, science must rest on the idea that all theories have the potential to be disproved.
Theory; Theory… But if something has the potential to be disproved, doesn’t that mean we’re unsure about its truth? Sure, if that something has very little evidence supporting it. But when something has a lot of evidence weighted overwhelmingly in one direction, the confidence we can exude in expressing its truth increases. Take a homicide investigation, for example, where the suspect was seen running out of a murder victim’s house 30 seconds after shots were fired, carrying a gun and covered in blood. Upon investigation, the man’s blood-covered clothes were retrieved down the street from the crime scene and DNA analysis confirms that the blood on the clothes was that of the victim. The suspect has no alibi and footprint analysis confirms that it was indeed the suspect who ran out of the victim’s house after the shots were fired. Several hours later, the police get a confession from the suspect that he/she committed the murder. Now, there is a chance that the suspect was inside the house saying hello to the victim, someone else shot the victim, covered the suspect in blood, the suspect stole the gun from the killer, ran away, ditched the clothes because they were dirty, and confessed because the police forced a confession; but this is a very unlikely scenario. In a homicide case as clear-cut as this, the evidence would “prove” that the suspect was guilty and would face the subsequent consequences.
The overwhelming evidence in the homicide example above is akin to the amount of scientific evidence supporting Evolutionary Theory. Although the suspect in the homicide would be “proven guilty”, scientists are reluctant to say that evolution (or any other theory for that matter) is proven. In essence, this is contributing (but is not the only contributor) to the lack of understanding amongst the general public as to what a scientific theory really is, and opponents of solid scientific theories (e.g., evolution and climate change) often manipulate the word “theory” to undermine scientific understanding. As Neil deGrasse Tyson says, “The theory of evolution, like the theory of gravity, is a scientific fact!” A theory is a fact! Yet the general public all too often grasps the word theory as something that is untrue, unsure, and extremely likely to change – this is not the case.
So is it time for science to shift its use of the word theory to something that can’t be manipulated to undermine concrete scientific concepts? Maybe, but science is the closest that we, as humans, can get to complete objectivity. Although absolute objectivity cannot be obtained, science allows us to try and explain how the world works with as little human bias as possible. As such, keeping some degree of skepticism, however small that degree might be, is critical to the faculty of science. Consequently, this minute degree of skepticism will always be exploited by those who argue against scientific reasoning. Ultimately, scientists should try and do a better job of communicating their science in a clear and concise way to keep the general public informed of the solidity of such “theories”, while the school system must equally inform children of what a scientific theory really is and why we know that “theories” are true accounts of the way certain things work.
But this is just a theory…