David's research is concerned with the evolutionary history of information processing mechanisms in biology and culture, with an emphasis on robust information transmission, signaling dynamics and their role in constructing novel, higher level features. The research spans several levels of organization finding analogous processes in genetics, cell biology, microbiology and in organismal behavior and society. At the cellular level he has been interested in molecular processes, which rely on volatile, error-prone, asynchronous, mechanisms, which can be used as a basis for decision making and patterning. He also investigates how signaling interactions at higher levels, including microbial and organismal, are used to coordinate complex life cycles and social systems, and under what conditions we observe the emergence of proto-grammars. Much of this work is motivated by the search for 'noisy-design' principles in biology and culture emerging through evolutionary dynamics that span hierarchical structures. In addition to general principles there is a need to provide an explicit theory of evolutionary history, a theory of memory accounting for those incompressible regularities revealed once the regular components have been subtracted.