The Finch and Pea

Any geneticist who has discussed genes with friends and family knows that there are a lot of misconceptions floating around out there. This is understandable – genetics involves some tricky concepts, and sometimes we use confusing linguistic shortcuts to talk about genes without using jargon. Sometimes scientists get confused as well (although that’s a topic for another day).

One of the big misconceptions is that there are genes ‘for’ specific traits — you’ll often hear that we have a gene ‘for’ X, X being some phenotypic trait. (If X is not a trait, but some sort of molecular player, than the language is correct, e.g. we do in fact have a gene — actually multiple genes — for the enzyme alcohol dehydrogenase.) This language is often rightly condemned as being misleading, because there is no one-to-one correspondence between genes and traits: traits are the product of multiple genes, while any given gene will contribute to multiple traits.

But you only need to tweak the ‘gene for X‘ language slightly to get at a correct and important concept in genetics: variation in a single gene is often responsible for important differences in X (in a particular population). This is usually what we mean when we say there is a ‘gene for X‘, but this clarification is rarely noted when people knock the phrase. Continue reading “Some gene conceptions and misconceptions”