Students do not come as tabula rasa, for teachers to fill up with facts. They have ideas about science already, formed by their experiences and interactions.
A few scientific topics are loaded with controversy because certain groups do not agree with the conclusions the scientific community have reached. Other scientific topics are made tricky because of common misconceptions or out-of-date understanding being widespread in the wider community. Many topics are controversial even amongst the scientific community.
Science teachers are equally blessed and cursed. We get the aura of Gatekeepers to All Scientific Knowledge while needing to break it to our students (gently?) that no one has all the answers and science is an ongoing process of working things out.
Evolution and Natural Selection is an especially tricky topic. Some people do not agree with the conclusions reached on religious grounds. There are some semi-scientific and pseudo-scientific groups who work to find fault with the topic. Nothing wrong with trying to find the limits of a topic but it must be done scientifically. Of course, as a work in process, the parts of the theory of evolution are being worked out. If a student believes that Science is a set of Things that are Known, controversy can be worrying.
Even the word “theory” causes problems. In everyday English, it means “idea” or “notion” or “hypothesis”. In scientific English, it means an explanation for a hypothesis that has not been proven wrong yet.
“Just a theory” is an especially infuriating phrase. There is no “just” about it, prove it wrong and then we can talk!
If scientists find an explanation for the variety of life on our planet that explains all the known facts better than ‘evolution’ does, then that will be the new theory I will teach in my classroom.
Most textbooks build on this idea of the scientific method relying on new data to build explanations that become more complete. Starting with Aristotle, going through Lamarck and ending with Darwin, usually.
I go a different route and teach about antibiotic resistant bacteria first. I do not use the words ‘evolution’ or ‘natural selection’. Most young people find the idea of bacteria evolving in a hostile environment completely uncontroversial. If I use the words ‘evolution’ or ‘natural selection’, some of my students will suddenly become more critical to the idea.
Depending on the age of my students, they can either learn about speciation, habitats and adaptation or genetics and inheritance. Once the groundwork is laid, I can talk about the history of evolution.
The problem with the Aristotle-Lamarck-Darwin timeline is that it completely ignores that many philosophers and scientists in between had ideas about evolution. There is not room in a curriculum to cover them all, of course. I usually bring up Epicurus because although he had ideas more in line with modern thought, he was still just philosophising and had no proof. Muslim scholars are worth a mention, especially since the Koran has “all living things come from water” (Koran 21:30)
This isn’t to say that I want to make my students godless or anything! Their religions are important to them and are a force for good in their lives. I just want to make sure that they have a deep understanding of how beautiful the theory of evolution really is. From where I am sitting, I think there is nothing to stop a deeply religious person appreciating the elegance of natural selection. In fact, many people have feelings of spirituality when they understand the mechanisms at work in populating our planet with diverse life and intelligent creatures who are able to appreciate it properly.
One of my students had his faith confirmed after I taught about the solar system and the ‘Goldilocks distance’ and how the Moon and Jupiter have protected us from many space object impacts. Understanding of scientific concepts is nothing to be feared.
Climate Change and Global Warming is another hot-button issue. Many young people will have parents that do not “believe in” anthropocentric climate change or have been exposed to information in the media which denies the science.
And indeed, much like natural selection, the theory is subject to new data. Whatever the personal beliefs of adults in society, young people have a right to know what the arguments are. They also have a right to understand the difference between weak and strong arguments.
For example, a scientific group who claim that climate change is happening more slowly than previously claimed are in a position to make a strong argument. Conversely, some man in a pub who claims that climate change isn’t happening because models on 1980s computers said the opposite and that means scientists cannot make up their minds, is making a weak argument.
As long as young people understand how scientific knowledge is assembled and interpreted, it actually does not matter to me if they align with current scientific thinking.
I start out by teaching them the difference between ‘weather’ and ‘climate’. If one more person says that global warming isn’t happening because it is snowy outside, I will scream. I also keep the phrase ‘global warming’ until the end of the topic. Even though the planet is warming, it can mean that local climates are colder or rainier. Until you understand that, the phrase ‘global warming’ is confusing.
Fairly early on in the topic, I will ask students to find a news item about climate change and critique it. Young people find critical thinking difficult at first. A simple question like “do you trust this news story?” can get all sorts of answers.
It is a good idea to give them space to air their feelings about the topic early on. There is nothing worse than being a student in a class who is trying to hold two ideas simultaneously. It is okay for students to say they don’t believe (or whatever), just so long as by the end of the topic they are able to defend their belief with science along with the students who buy into the current scientific understanding. There are plenty of scientists who disagree with the current consensus. It is important that my students understand why. I don’t want them quoting orthodoxies, I want them thinking!
Giving space and permission to ‘disagree’ with the teacher also gives the opportunity to see if there any misconceptions floating around. For example, climate change on other planets, sun spots and ice cap cycles.
What are your ‘tricky’ topics? What do you do to teach them? How do you approach your students?