When should we talk about Mendel and his peas?

Presenting historical moments in science is firmly embedded in our teaching practice, often teaching developments in chronological order. A good example of this is the teaching of genetics, which often starts with Mendel and his peas, dominant and recessive alleles and punnett squares.

This topic is often covered before discussing the concept of the genome. But is this approach effective? There has been a lot of research into and debate over the idea of an “inverted” genomics curriculum and the impact this can have on a student’s understanding of genomics. This has been advocated by Duncan, Castro-faix and Choi (2014) who present evidence that teaching molecular genetics before introducing Mendelian inheritance is advantageous for students.

So why could this be? As mentioned traditionally many children learn about single gene (Mendelian) inheritance before finding out about the function and mechanisms of genes and their relationships to phenotypic traits. This can lead to an overreliance on a deterministic way of thinking about the importance of genes and the roles that they play in complex diseases. Whereas introducing molecular genetics concepts and even topics such as the proteome can lead to a better progression of learning and understanding.

The diagram below is taken from Carver et al 2017 and shows that developments in genomics research has shifted our thinking away from genetic determinism.

However if mendelian genetics is still put front and centre when teaching genomics it has the potential to cause students challenges later down the line. What do you think?

A really interesting piece “Why do we have to learn this Stuff” – A new genetics for 21st Century students by Rosemary Redfield (2012) encourages this debate. It discussed how Redfield restructured an undergrad curriculum to teach molecular genetics first, stripping out mendelism and focused on what students will need in their daily lives to have “a solid understanding of how genes influence phenotypes, natural variation and the mechanisms of heredity”. If you have time we recommend you take a look.

Discussion forum What are your thoughts on this debate? When in your genomics teaching do you introduce mendelian genetics? Would you consider reordering the teaching sequence?

Share your ideas.