Iron in evolution

► This paper sets out the contribution of Antonio Xavier to iron biochemistry. ► It then puts this work in the context of the way iron has been involved in the evolution of the combined system of organisms/environment. ► The analysis of the environment is based on the examination of the element content of sediments over the ages. ► The study of organisms relies on knowledge of known or deduced element composition of fossils, in gene extrapolation and comparisons of extant organisms. ► Putting the two together shows that they are one system.