This idea became known as PI, standing for positional information, the champion of which was a developmental biologist named Lewis Wolpert. Born in South Africa in 1929, Wolpert, after first training as a civil engineer, switched to biology at King’s College London, where he completed a PhD in the mechanics of cell division. PI, unlike Turing’s theory, requires no complex mathematics. It hypothesizes that morphogens of different kinds exist in varying concentrations in different parts of the embryo. The concentration of a particular morphogen at a specific point causes a cell to develop one
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