So I’d actually disagree. I think we know most of the fundamental principles of biology. The basic ideas underlying genome replication, RNA expression, and protein translation are very well understood. These are the core defining processes of life and we’ve basically figured out their most important, most highly conserved interactions.

The trick with biology is figuring out how these processes are controlled. Every aspect of cellular behavior has absolutely enormous combinatorial complexity. Take the EGFR protein for example. Its a receptor protein that seems to be important in controlling growth of cells. The EGFR protein has (I believe) at least twenty different locations that it can be modified. Each modification changes it’s shape and the other proteins that it can interact with. Each combination of interactions, in fact. So this one protein has at least a million different possible variants. Then consider that there are at least 20k different human genes and there are many many different ways that interactions between proteins, genes, and RNA are modified and regulated. Again, all the fundamental processes are understood, like we understand how EGFR gets modified. These processes are combined and remixed in an absolutely astronomically huge variety of ways.

Biology is just insanely fucking complex.