Mutations are genetic alterations that drive biological evolution and cause many, if not all, human diseases. Mutation originates via two distinct mechanisms: "vertical" variation is de novo change of one or few bases, whereas "horizontal" variation occurs by genetic recombination, which creates new mosaics of pre-existing sequences. The Mutagenesis Conference has traditionally focused on the generation of mutagenic intermediates during normal DNA synthesis or in response to environmental insults, as well as the diverse repair mechanisms that prevent the fixation of such intermediates as permanent mutations. While the 2004 Conference will continue to focus on the molecular mechanisms of mutagenesis, there will be increased emphasis on the biological consequences of mutations, both in terms of evolutionary processes and in terms of human disease. The meeting will open with two historical accounts of mutation research that recapitulate the intellectual framework of this field and thereby place the current research paradigms into perspective. The two introductory keynote lectures will be followed by sessions on: (i) mutagenic systems, (ii) hypermutable sequences, (iii) mechanisms of mutation, (iv) mutation avoidance systems, (v) mutation in human hereditary and infectious diseases, (vi) mutation rates in evolution and genotype-phenotype relationships, (vii) ecology, mutagenesis and the modeling of evolution and (viii) genetic diversity of the human population and models for human mutagenesis. The Conference will end with a synthesis of the meeting as the keynote closing lecture.

Each session will have a Chair who will introduce the subject of the session and each of the speakers. The session Chairs will be chosen not only for their scholarly view of the field, but also for their ability to initiate and encourage discussion among all participants. The invited speakers in each session will describe recent (primarily unpublished) results from their labs, but will be asked to integrate their personal research into a critical and creative overview of their research area. The session Chair will moderate a short discussion period immediately following each speaker's talk. "Hot topics" chosen from the submitted poster abstracts may also be selected for short (5 min) presentations. Finally, each session will end with a general discussion led by the Chair. The open discussions are viewed as a critical component of the Conference that sets it apart from other, larger conferences.