There must be something fixed in the learning process.

Something about the learning process must be hardwired, too, drawing the birds towards the same song patterns again and again. This means that basic information about the zebra finch song must be stored somewhere in its genome, imprinted there by millions of years of evolution. At first, this might seem odd, as we usually think of genetic code as a source of biochemical or physical traits, not something like a behavior or action. But the two aren’t fundamentally different; we can connect genomes to behavior through brain circuitry. The connection is noisy and quite complex. It doesn’t simply map single genes to single behaviors, but it exists.