6. Genes

There is no satisfactory one-line answer to the question ‘what exactly is a gene?’. The reasons why a precise definition is elusive are particularly interesting, and raise a number of philosophical subtleties. ‘Genes’ delves briefly into the history of genetics in order to understand them. It first looks at the work of Gregor Mendel in the 1860s and then the era of classical genetics in the 1920s and 1930s. It then moves on to molecular genetics, which came to fruition in the 1950s. How does the gene of Mendelian or classical genetics relate to the gene of molecular genetics? This question has long occupied philosophers of biology.