Big ideas in science: Evolution

The theory of evolution by natural selection is one of the ‘big ideas’ in science (you can read more on the Association for Science Education's website).

It acts as a framework, connecting all aspects of biology and explaining the diversity of life, the relationships between organisms and the processes that have shaped the living world. The English National Curriculum only introduces evolution as a topic in Year 6, but the foundations for understanding it can be laid throughout primary-level science.

With support from the Evolution Education Trust, we’ve mapped out topics in the primary science curriculum where the foundations of key concepts in evolution can be introduced and the development of misconceptions avoided. We have also produced several resources to support teaching evolutionary concepts across primary science.

Classroom activities

Why introduce such a complex topic so early?

Children are naturally curious. Evolution provides answers to many of the ‘why’ questions about the living world. Teaching children about evolutionary processes gives them tools to start unpacking their own questions, and research such as this study in the journal Early Education and Development shows that children are capable of learning them.

Many core concepts necessary for understanding evolution are already introduced in primary school science. Approaching topics such as habitats or adaptations with evolution in mind brings them together, building a clearer progression and setting the stage for more complex learning later.

Teaching these topics without considering how they lay the foundations for evolution may leave children with misconceptions that impede their later learning. See this literature review in the journal Studies in Science Education, where researchers identified some of these problematic cognitive biases.

Potential misconceptions in primary school

Essentialism

This is the idea that a species has some core-essence that defines it and does not change from generation to generation. This idea often leads to students overlooking variation within a species and makes it harder to understand that species can change over time, as was noted in an article from the journal Evolution: Education and Outreach.

For teachers, it may help to keep in mind that the description of a species represents a snapshot in time. In fact, the definition for a particular species is often based on a type specimen – the specimen that was first used to describe the species, which all other specimens are compared to. (Read more about type specimens on the Carnegie Museum of Natural History's website.)

If you were to look back at earlier generations or forward at their descendants, there will come a point where small changes in their features and genetic code will mean they begin to fall outside of the definition for that species.

You can read our article, What is a species? to find out the different ways scientists have of defining what species are.

For students, classification activities that include examples of differences between individuals of a species can act as a reminder that natural variation exists. Focusing on key features when doing classification is less likely to reinforce an essentialist understanding of species and will help to develop better observation skills.

Survival of the fittest means the strongest or the fastest

This misconception comes partly from the word fitness having a slightly different meaning in the context of evolution and ecology.

In everyday use, fitness is about strength, speed or endurance. However, in the context of evolution or ecology, fitness is about being able to survive and reproduce. There are many ways for organisms to survive long enough to reproduce, many of which have nothing to do with physical strength or speed.

Students should be encouraged to think about the range of strategies an organism might have for getting what it needs to survive and reproduce.

Learning about adaptations should also explore chance and probability. This counters the misconception that fitness is a binary: that an organism is fit or adapted to an environment, or it is not.

For example, students may misinterpret an animal being camouflaged to mean it is undetectable by predators when, in reality, it only reduces the chances of being spotted and it is only one way that animals can avoid being eaten.

Read our article What is natural selection? for how natural selection acts as a mechanism of evolution.

Why is evolution important for students?

Bringing together biology topics by thinking of them through an evolutionary lens helps students develop scientific literacy, as the authors of this article in the journal Evolution: Education and Outreach argue.

Understanding evolution is about understanding processes and systems. The large-scale, long-term thinking required to understand evolution is the same perspective needed when considering some of the biggest problems that humans face today.

Learn more about the relevance of evolution in these pages from UC Berkeley.

Conservation efforts

For example, evolutionary principles are vital for conservation efforts. They help us understand how species have adapted to their habitat and how they might respond to climate change. This knowledge is essential for developing strategies to better target conservation efforts, adapt to the changing climate and maintain our planet’s rich biodiversity.

You can read some useful articles we have touching on conservation:

• Unlocking wheat’s genetic secrets to feed the world
• Risks of amphibian extinctions from climate change rising rapidly

Human health

Understanding evolution is essential for improving human health. For example, antibiotic resistance in bacteria is a prime example of rapid evolution. Understanding the evolution of viruses can guide the development of effective treatments and vaccines.

The evolutionary relationships between organisms can help us predict where diseases might hop from one species to another , and then to humans (a zoonotic disease).

Evolutionary theory is even being used to advance cancer therapies. It helps us understand how cancer evolves in our bodies to evade our natural defences and scientists are exploring how to develop therapies that boost our immune system to combat that.

Some relvant articles we have on this topic:

• Climate change could cause diseases to gain new hosts
• What happened during the 1918 influenza pandemic?