Evolutionary immunobiology.

Identifying the evolutionary origin of inducible, specific immune recognition represents a major objective in developmental immunology. In order to address this issue from an overall phylogenetic perspective, major studies of cellular and humoral immune function are being undertaken using lower vertebrate and invertebrate models. Here, C. Reinisch and G. Litman discuss the application of new technologies, particularly molecular genetic approaches, that is providing important new insights into the genetic mechanisms that have influenced the evolutionary diversification of immunological function.