The 2004 Genetics Society Medal has been awarded to Peter Holland, Linacre Professor of Zoology in the University of Oxford. The Genetics Society Medal is a new award which recognizes outstanding research contributions to genetics. Peter Holland has made, and continues to make, an outstanding contribution to Genetics through his analysis of genomes. His research work has combined outstanding molecular genetics, often performed on non-standard organisms, with a deep understanding of evolutionary biology and great zoological knowledge. Peter Holland has worked in three main areas: the role of gene duplication in vertebrates origins, novel homeobox gene clusters and the origins of multicellularity. These are fundamental issues in development and evolution, and Peter Holland has made important discoveries about all of them.