Professor Speed has made a number of original contributions to statistics and genetics. He developed new approaches to modelling and depicting complex dependence relationships between arbitrary collections of random quantities, and much of the now active field of graphical and causal models builds on his research. He created new algebraic tools to extend and simplify the standard theory of analysis of variance. In genetics he has clarified the notion of genetic map function and significantly broadened the class of tractable stochastic models of genetic recombination. At the same time he has also carried out and published many innovative statistical analyses.