John Dupré explores recent revolutionary developments in biology and considers their relevance for our understanding of human nature and human society. Epigenetics and related areas of molecular biology have eroded the exceptional status of the gene and presented the genome as fully interactive with the rest of the cell. Developmental systems theory provides a space for a vision of evolution that takes full account of the fundamental importance of developmental processes. Dupré shows the importance of microbiology for a proper understanding of the living world, and reveals how it subverts such basic biological assumptions as the organisation of biological kinds on a branching tree of life, and the simple traditional conception of the biological organism. These topics are considered in the context of a view of science as realistically grounded in the natural order, but at the same time as pluralistic and inextricably integrated within a social and normative context. The volume includes a section that recapitulates and expands some of the author's general views on science; a section addressing a range of topics in biology, including the significance of genomics, the nature of the organism and the current status of evolutionary theory; and a section exploring some implications of contemporary biology for humans, for example on the reality or unreality of human races, and the plasticity of human nature.