When you stop at a traffic signal, the relevant boundary conditions reside in institutional constraints, extensive bodies of text. Law, religion, and academia are complex expressions of textual constraint in human culture. The sequential constraints governing institutions often have a terrible reputation, ignored with impunity and publicly disdained. We are physical, biological, social, and institutional creatures, and our behavior is an ongoing free-for-all among the relevant constraints. Dawkins proposed the meme as a replicating unit of culture analogous to the gene as the replicating unit of biology, but there is a difference between snippets of culture and self-referential text-based institutions. Viruses are recipes, molecular memes; they comprise a list of ingredients and a set of rules. Like horizontal gene transfer in the cyanobacterium Prochlorococcus, humans float in our own information soup of memes, inputting them, expressing them, and replicating them. Individual particulate memes and recipes hop from person to person, but systems of sequences generate regularity of behavior in institutions. The finely tuned gene regulatory networks of living things and the pervasive institutions of human culture follow an evolutionary trajectory distinct from the sequence snippets of horizontal gene transfer and the spread of memes like tunes and clothes fashions.