DNA, it’s what makes us, well us! Not that long ago, before we sequenced human DNA we assumed we had one of the largest genomes around. Frankly it wasn’t a bad assumption, but of course we found out this was far from the case and to make ourselves feel better we said size doesn’t matter. But one of the surprising discoveries to emerge from comparative genomics is that drastically different organisms–humans, sea urchins, worms, flies –are endowed with a more or less common set of genes. So given a similar DNA blueprint, how do species develop such vast differences in physical shape, size, and complexity?