Misconceptions
Many misconceptions have been developed through time about evolution. Some being simple misunderstanding ideas that developed in the course of learning about evolution either in a classroom setting, media, or even small debates between one another. Even though misconceptions are building up slowly over time, their effect can impair student understanding of evolution. This can lead to students being confused and doubt evolution or science in general once they leave school. Below are listed some of the misconceptions about evolution and how to address these misconceptions in your class.
Misconception #1: Natural Selection & Evolution are the same thing.
These two terms do not possess the same meaning. In fact, evolution is described as any change in the distribution of heritable traits within a population over time. On the other hand, natural selection is one important mechanism of evolution, along with genetic drift, gene flow, and mutation.
How to address it?
When discussing evolution in your class, be sure to emphasize that natuarl selection is one of the mechanisms of evolution along with the others. For example, when teaching your students about the diversification of the finches in the Galápagos islands, you not only cover natural selection but also genetic drift. Be sure to stress on the terms when using them and explain clearly that these two terms are mechanisms of evolution. Have your students read the case study on African Elephants, then have a class discussion about it. Ask your students what have they learned? if you hear your students interchanging the two concepts and terms as if they are synonymous, correct them. Point out mutation and how its a mechanism of evolution and emphasize with clarity that natural selection is also another mechanism of evolution.
* Watch this video to help overcome this misconception.
Misconception #2: All traits are adaptive.
In the evolutionary sense, to be adaptive means that a trait has to meet a certain criteria when it shows up in a population; has to be heritable and functional and has to increase an individual's fitness. However, there are some traits that don't possess a function and they are simply byproducts of something else. For example the belly button, which has no function but instead it is just a scar from the umbilical cord. Another example being the human tailbone which is a vestigial structure that performed an important function at one point in the past.
How to address it?
One way addressing this misconception is to point out clear examples of non-adaptive traits such as belly buttons and male nipples. Have a discussion with your students and let them think for a few minutes what function does the belly button or the make nipple serve. The students will not know the answer, which is important to mention to them "not all traits are adaptive". Provide as many examples as possible to stress this misconception, for example Whale hip bones. Provide the students with a picture just like the one below so students can visualize it. Also, the video below points out other structures in the human body that has no function. Through discussion and visualization, you can address this misconcepion since there are many clear examples that can be pointed out to correct "all traits are adaptive".
Figure 7: Large whale have vestigial hips that no longer serve any function.
*watch the video below that addresses vestigial structures.
Misconception #3: Organisms are always getting better through evolution.
Natural selection being an important mechanism of evolution does result in the improved abilities to survive and reproduce. However, this does not mean that evolution is progressive because natural selection does not produce organisms perfectly suited to their environments. Natural selection allows the survival of individuals with a range of traits that are "good enough" for individuals to survive. Additionally, other mechanisms like mutation, migration, and genetic drift may cause populations to evolve in ways that are actually harmful or make them less suitable for their environments.
How to address it?
The best way to addressing such misconception is by providing the students with real life examples. Start of with a small discussion with your student about whether or not they believe that organisms get better through evolution. Let the student write down a few points that supports their opinion on this misconception then take it up as a class. Students may still not grasp that not all organisms are always getting better through evolution. Use the link below as an acitivty to address such misconception. The "Golden Toad" article discusses the reasons behind the extinction of this species. Even though one reason was due to human activity, the other was due to nature and the changing environment. The article discuss in details how their environmental climate changed and lead to this species going extinct. Read this article as a class and have a discussion by using the Golden Toad as an evidence that NOT all organisms get better through evolution