Could be something like: 1. hardwired for creating visual models of 3d / 2d space 2. hardwired for fine-grained hand motor movements. So the learning is just

Could be something like: 1. hardwired for creating visual models of 3d / 2d space 2. hardwired for fine-grained hand motor movements. So the learning is just combining those two skills into the ability to make the brush strokes needed to output the model onto paper.