Evolution – Getting Started

Flickr photo credit: digital vilikki

Evolution can be a stressful topic for many biology teachers in the United States due to the perception of controversy surrounding the theory.   I’m also making mention of the U.S. here because peers I have spoken to in other countries seem surprised to learn that there is even an issue about it.    Regardless of how we got here, you can eliminate a lot of the stress and controversy if you start  the topic out right.

A common mistake beginning teachers have is to start out asking about questions and viewpoints the first day of evolution topic.  I say this is a mistake because at this point, students probably don’t know much about the actual theory and will only repeat what they have heard or repeat misinformation that can serve to not only muddy the waters, but turn the class into a debate-zone – neither of which are desirable at this time.

This year, when I began class stating that we would be studying evolution next, about four little hands popped up from students who felt they had to tell me right then an there that “they didn’t believe in evolution”.    I do not let them talk or debate it, instead I just say “it doesn’t matter whether you believe it or not,  you are required to learn it”.  This tends to deflect the issue as students are given tacit permission to not believe if they so choose.    You’ll find as the unit progresses, this idea of “belief” will go away on its own.  And by the end of the unit, students may be at a better place to have an intelligent discussion about the compatibility of the theory with religious beliefs.  What you do not want to do is start your evolution unit off with this type of discussion, as it will quickly spiral out of control and you will become sidetracked dealing with a myriad of myths and misinformation.
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Start with defining evolution in its most simple terms – CHANGE OVER TIME.    Point out that this definition should not be controversial at all and should even make sense.  As the earth changes, as climates change, animal species must be able to adapt to those changes to survive.   Those species that cannot adapt become extinct and the fossil record has tons of evidence of animals that became extinct, such as the wooly mammoth or dinosaurs.    If you have a projector, you can also show pictures of these extinct animals and ask students why the animals may have died off.

The important part with starting evolution this way is that none of it is going to prompt the frantic hand raising, angry mob of younsters who must express that they do not believe in evolution.  Start with simple concepts that are not controversial and that students can understand.   Also, throw in dinosaurs – kids love dinosaurs and they love discussing why dinosaurs became extinct.

This is also a good time to review with students what a scientific theory is.  You may have already discussed this during early chapters, but bring it up again.  Stress that in science a THEORY is not a guess.   A theory is developed through many experiments and observations.  The theory of evolution by natural selection was first proposed by Charles Darwin, but many other scientists from many other disciplines (chemistry, geology, genetics) have since added to our knowledge and understanding of the theory.

Once you have established that evolution is CHANGE OVER TIME, then you can move forward to discuss the nuts and bolts of the theory – how the change happens through NATURAL SELECTION.   Again, natural selection by itself is not controversial and can be explained in simple terms.   My next post will cover how to easily explain natural selection in terms that a beginning biology student can understand.

In the meantime, now might be a good time to brush up on your own understanding of evolution – here are some sites that can be helpful for both teachers and students

Evolution – companion site for PBS series on evolution, has video clips
Darwin’s Darkest Hour – NOVA production and website
Berkeley’s Evolution 101 – guide to all things related to evolution