textbook evolution

In 2002, school officials in Cobb County, Georgia placed stickers with this text inside a set of biology textbooks:

“This textbook contains material on evolution. Evolution is a theory, not a fact, regarding the origin of living things. This material should be approached with an open mind, studied carefully and critically considered.”

By saying that evolution is “just a theory,” the stickers lead people to believe that the theory of evolution is nothing more than a proposed guess that can be easily discredited. But that’s not the case at all – a significant amount of evidence exists behind the theory of evolution.

Herein lies the problem: different ideas of what a “theory” is creates a disconnect between scientists and the rest of the public. “Theory” is used by both scientists and the public, but it has a different meaning depending on who uses it. This has wide-spanning implications for how people perceive science.

In everyday usage, theory is defined as a belief or an idea someone has, that has not been tested and doesn’t have weight behind it, In the scientific world, however, theory takes on an entirely different meaning. According to the National Academy of Sciences a theory is a well-substantiated explanation of some aspect of the natural world that can incorporate facts, laws, inferences, and tested hypotheses.

To a non-scientist, a theory is an idea that can be easily refuted, whereas to scientists, a theory is an almost irrefutable law of nature. This does not mean that a scientific theory is an undeniable fact. Science by its nature contains uncertainty, so no theory can ever be 100% true. Nonetheless, to scientists, theories are as close as we can get to fact. This is why only a few ideas actually become theories, with only about 100 theories existing today, even after thousands of years of human observations.

To a non-scientist, a theory is an idea that can be easily refuted, whereas to scientists, a theory is an almost irrefutable law of nature.
Observations can also have different monikers, depending on how advanced they are. For example, the meaning of hypothesis is closest to what everyday language currently labels theory. When people say, ‘I’ve noticed ABC, my theory about it is…’ in science it would be stated as ‘I’ve noticed ABC, my hypothesis about it is….’  A scientific hypothesis is a proposal, a sort of educated guess. A theory has a lot of scientific evidence and studies backing it; a hypothesis does not.

Sometimes hypothesis and theory are treated as synonyms and ideas that are really just hypotheses are labelled as theories. Think of the ‘creationist’ theory, which is the religious belief that the universe originated from a divine creator. Remember that a theory is an idea that has been rigorously and repeatedly tested using the scientific method. By definition, then, creationism is not a theory. This does not mean evolution must be right because it is a theory, nor that creationism is wrong because it is not a theory, but it does change the conversation that opposing groups may have. It would be helpful for all parties to have a scientific discussion about the evidence that exists, because without discussing the science no progress on either side is made. Including more people and more viewpoints in the conversation will strengthen the impact of science for everyone.

Even reputable sources sometimes use the word theory incorrectly in a scientific context. For example, in the Freakonomics episode ‘Chuck E. Cheese’s: Where a Kid Can Learn Price Theory’ hosts Stephen Dubner and Steven Levitt talk about price theory, a well-substantiated theory which says that in a free market economy, supply and demand determine the price of items. However, the hosts also mention theory in many other contexts when hypothesis would be a better word. For example, at one point this exchange takes place:

Dubner: “Okay, so how should the theory be tested?”
Levitt: “You could try to run some experiments.”

In this example the hosts are discussing the scientific method, and they present the word theory in a scientific context as an educated guess meant to be tested. They are also unconsciously cheapening price theory as just a guess, and that’s where the problem really lies.  Freakonomics generally does a great job of being precise, but this shows that even careful, scientifically educated people can perpetuate the idea that a scientific theory is just a guess.

Fortunately, there’s a simple solution to this problem. We can reframe the everyday definition of theory to better fit the scientific definition.  Language is an ever-adapting medium of communication, so not only is this possible, it’s not difficult to accomplish. John McWhorter, a linguist and Associate Professor of English and Comparative Literature at Columbia University, summarizes this idea perfectly:

“…it’s the nature of human language to change. Each generation hears things and interprets things slightly differently from the previous one.”

What this means is that as language speakers, we modify language. As a society, we can take advantage of this quality of language to reframe how we talk about theories and hypotheses. People can substitute the word theory for the word hypothesis if hypothesis better describes the situation. Teenagers modify words all the time – take the adaptation of the word “literally” to mean “figuratively!”

This may seem as though language is being used incorrectly, but because language is not static, these changes are in many cases inevitable, and in no cases ‘wrong’. Take the word gay, for example. No one would argue that today, this word refers to homosexuality. A few hundred years ago, people would call that definition wrong, as it referred to a state of happiness. There are various reasons to change language, and doing it to clarify the strength of ideas is a good reason. These changes don’t take a long time either; every few years, the lexicon used by kids changes pretty drastically. The simple substitution of hypothesis can help to better the relationship between science and the public. With diligent awareness, it can happen within a decade.

In 2005, three years after the stickers were first placed in the Cobb County biology books, a federal judge ordered that the stickers be removed on the grounds that they unconstitutionally endorsed religion. Unfortunately, there are other states where this happens, such as in Louisiana and Tennessee, and such misunderstandings between scientists and the public continue to be an issue throughout the United States. While ensuring that the word theory is used correctly will not solve all of these misunderstandings, it is a step forward to improving the perception of science. At least, that’s my theory – I mean, hypothesis.

By Aroob Abdelhamid

http://www.nbcnews.com/id/6822028/ns/technology_and_science-science/t/judge-nixes-evolution-textbook-stickers/#.WOKg6vnyvicfreakonomics.com/podcast/chuck-e-cheeses-kid-can-learn-price-theory/ http://www.pewforum.org/2009/02/04/fighting-over-darwin-state-by-state/http://www.merriam-webster.com/words-at-play/misuse-of-literallyPicture from: ncse.com/files/images/CobbDisclaimer_864x437.preview.jpg

Posted by Science Buffs

A CU Boulder STEM Blog

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