Thread by @thattai

I've been searching for a good metaphor to explain what genes are. Hear me out. (No doubt, someone has thought of this before.)

Think of an orchestra.

There are players -- these are the laws of physics and chemistry.

There's a symphony -- this is the organism.

Finally there are the instruments -- these are the genes.

During a performance, each instrument is played intermittently. This has to do with how the composition plays out, how everything works together.

This is the development of the organism.

Some pieces (say, a blues standard) can be played with just a few instruments. Others (say, Beethoven's 5th) require a larger orchestra.

Don't confuse the number of genes with the complexity and subtlety of the organism.

Most instruments have their quirks; they're slightly out of tune. This adds to the nuance of any piece.

Genes have point mutations; this leads to varying outcomes for the organism.

People confuse the idea of having an instrument in the repertoire, with the idea of playing an instrument intermittently in a performance.

The existence of a gene and its experession over the life of an organism are very different things.

Sometimes instruments change. The harpsichord led to the piano.

Sometimes instruments appear out of nowhere. The steel drum was repurposed out of junk.

Recording adds a layer of complexity. Riffs can be reused.

Remixing is key. New combinations work in unexpected ways.

This is variation.

Ultimately, the audience is moved by the performance; or not.

This is natural selection.

It's not a perfect metaphor; nothing ever is. But (compared to "blueprints" or "programs" or "circuits") I think it gets closer to the heart of things, closer to the structure of life.