by: Carol Hurney
One of the most beautiful aspects of my discipline is the process of critically analyzing the scientific method. Yes, the scientific method. Wait, wait! Don’t run away from this article screaming – OH NO!!!! NOT THE SCIENTIFIC METHOD??!?! Just relax. And why would you want to avoid a probing analysis of the scientific method? Why does this topic sound so, well … boring? Maybe because every science class you ever took started with a list of steps that the teacher referred to as the “scientific method?” The list seemed simple enough – observe, generate hypotheses, design experiments, etc. Unfortunately, it failed to stimulate any sort of interest or excitement. How unfair. Why does the most fabulous part of my discipline get SO short-changed when compared to more seemingly exciting topics like dolphins, HIV, and killer bees? Why? Because really understanding the beauty, power, and complexities of the scientific method is hard and is SO much more exciting than what you learned in your science classes. Now don’t get me wrong, it is pretty easy to memorize a list of steps, but it is not so simple to become a scientific critic. I know my degree says that I am a biologist, but I am really a scientific critic. Sure, I know some stuff about biology, but more importantly I know when to believe the results of a scientific experiment and when the results of a scientific study should be thrown in the trash. Yes, some science is disposable. Unfortunately, bad, disposable science doesn’t have funky odor, grow green, slimy mold, or look that different from authentic science. So, how do you know when science is disposable?
You can’t simply dispose certain scientific findings or discoveries because you don’t like them or they don’t align with your needs. Every time I teach GBIO103, the non-majors general education course, I ask my students whether they regularly get the flu shot. I continue to be shocked that a large majority of my students never get the flu shot. When I ask why, they tell me things like… “I don’t get the flu.” or “I don’t like needles.” or “The flu shot isn’t 100% effective.” I laugh heartily at the first response. Who knew you could just decide whether or not you get an infectious disease. The second response is valid and I understand that some people have a fear of needles. But the last response indicates that my students are disposing the scientific evidence supporting the efficacy of the flu vaccine. The scientific evidence on the efficacy of the flu vaccine is varied and reasonably solid, but never claims that the vaccine is 100% effective. Unfortunately, the methodologies used to analyze the ability of the flu vaccine to prevent the flu are well, messy. Just to refresh your memory the scientific method suggests that one way to meaningfully test a hypothesis is to perform a controlled experiment. This concept of a control doesn’t mean that scientists control all aspects of the experiment, like what time of day the vaccines are administered, what the subjects eat for breakfast, and so on. Rather, the control is something you can compare the results of the experiment to so that you can be sure that the effect you observe is meaningful. In this case, a control would be a group of people who don’t get the flu shot, but do get direct exposure to the flu virus. Yikes! Who wants to volunteer for that group, especially since in some cases the flu can be fatal? So, instead of performing controlled experiments, researchers often test the correlation between two variables. In the case of the flu vaccine, there is strong positive correlation between getting the flu vaccine and NOT getting the flu. Do some people who get the flu shot still get the flu? Yes. Does that mean that the vaccine isn’t effective? No. It just means that for some reason, the vaccine didn’t provide enough protection or was not administered in time. Likewise, there are lots of people who don’t get the flu but did NOT get the vaccine. In my opinion, they were lucky. But that doesn’t mean that they “just don’t get the flu.” Rather, it means that they weren’t exposed to the flu virus or if they were, their immune system was able to defeat the infection with little or no symptoms. Ultimately, your opinion doesn’t influence whether science is disposable. But your INFORMED opinion does! Yes, you can decide whether science is disposable, but only if you really explore and critique the methods used to make a scientific claim. How do you do this? Well, you start by becoming a skeptic AND seeking out reliable scientific resources. Google is good for some searches, but don’t rely on this search engine when you are looking for good science. Most university libraries maintain wonderful websites with all sorts of reliable databases where you can begin your hunt for the real science behind the headlines. And don’t expect that you will understand everything you find, but in time you will start developing the skills to dispose of some science.
Once you begin critiquing the scientific methods used to test hypotheses, a whole new world will open itself to you. At some point along this journey, you will begin to appreciate the true challenges of the scientific method. And every so often, you will come across a stunningly beautiful scientific study. Beauty in science is not simply a visual pleasure, but is often found in how scientists execute their work. One of my favorite examples of scientific beauty is the famous experiment performed by Alfred Hershey and Martha Chase in the 1950’s. Using nothing more than a simple household blender and some radioactive elements, these two scientists confirmed that DNA is the genetic material. They were not the first scientists to test the hypothesis that DNA, not proteins, carried the information for inheritance, but they were the first to design an experiment that left even the staunchest critics speechless. Scientists knew that a simple virus, called the T2 phage, could infect bacteria with a molecule that genetically altered the bacteria. Hershey and Chase reasoned that if they could determine which molecule the T2 phage injected into the bacteria, they could put the DNA versus protein debate to rest. Hershey and Chase also knew that the T2 phage is composed of only DNA and protein, thus simplifying their analysis by minimizing extraneous variables. To test the hypothesis that DNA is the genetic material, they generated two versions of the T2 phage. One version contained radioactive DNA and the other contained radioactive proteins … the perfect control. They mixed each type of phage with bacteria, separated the T2 phage from the bacteria in a blender, and then determined which bacteria were radioactive. Every time they performed this experiment they got the same result. Only the bacteria infected with phage containing radioactive DNA contained radioactivity. Thus the T2 phage was injecting DNA into the bacteria creating genetic changes to the bacteria … simple and beautiful confirmation that DNA is the genetic material. Success! How beautiful?
When scientists explore the efficacy of the scientific method, ponder the results of an experiment, or marvel at new scientific discoveries they undoubtedly are looking for any reason to discount, disprove, or dismantle. I didn’t always do this – but now I do it so often, that my closest friends are growing weary of my constant skepticism of well, just about everything. This can’t be a good way to look at the world … or is it?