It seems likely that I was invited to contribute to this course because I am a renegade geologist. Many years ago I was lured by the attractions of living animals and switched to zoology. Later I became interested in the possibility of using immunological methods to assess evolutionary relationships among shrews, moles, hedgehogs, tree-shrews, elephant-shrews, otter-shrews, golden-moles and tenrecs, and I set a graduate student onto this project. We also sought to explore the relationships between these so-called ‘Insectivora’ and other orders of mammals, using immunological techniques to estimate crude biochemical distances between the serum proteins of representative species.