How proteins recognize specific stretches of DNA is one of the key questions of gene regulation. One would like to be able to look at the regulatory DNA sequence adjacent to a gene, and predict which regulatory proteins bind there, and control the adjacent gene. In other words, we want to, just by running a few computer programs over a genome, know how the genes in that genome are regulated.

An interesting phenomenon in growing random networks:

The number of 3-node, 3-edge connected subgraphs in a random, scale-free network of N nodes scales as N⁰ (=1). No matter how big your network grows, you're going to have a roughly constant number of 3-node, 3-edge  subgraphs that depends only on the ratio of edges to nodes.

Let's back up a minute before we see why this counterintuitive result is so and what it means.  Imagine that we have a network made up of N nodes connected by E edges. You can start out with two nodes connected by one edge:

David Brooks takes on evolutionary psychology and gets it sort of right:

The first problem is that far from being preprogrammed with a series of hardwired mental modules, as the E.P. types assert, our brains are fluid and plastic. We’re learning that evolution can be a more rapid process than we thought. It doesn’t take hundreds of thousands of years to produce genetic alterations.