We use a highly integrative approach in evolutionary biology to understand how biological diversity is generated as a result of historical processes. Linking development, ecology, and population genetics can provide insight into the mechanisms that result in novelty and at the same time reveal the principles of divergence. Using the free-living nematode Pristionchus pacificus as a model and combining laboratory studies (forward and reverse genetics, genomics, transgenesis) with field work (ecology and population genetics), we investigate evolutionary processes using an interdisciplinary approach. Among several research areas, developmental plasticity as a facilitator of phenotypic diversification and the evolution of novelty are our current focuses.
Developmental plasticity describes the property of a given genotype to produce distinct phenotypes in response to environmental variation. During the past two decades, a theoretical framework has been built that highlights plasticity as a key concept in evolutionary biology. Specifically, studies of plasticity can provide unique insight into i) the origin of novelty, ii) the environmental influence on development and evolution, and iii) the mechanisms of developmental canalization (following evolutionary pulses of plasticity). However, mechanistic insight into plasticity is scarce because few model systems allow genetic and mechanistic insight. We have established P. pacificus as a model system for plasticity research with unique properties. Our work aims for a mechanistic understanding of developmental plasticity and its conceptual integration into evolutionary biology.
Such conceptual integration requires i) mechanistic studies in developmental genetics, ii) chemistry, and iii) epigenetics, as well as phylogenetic approaches using iv) micro-evolutionary and v) macro-evolutionary comparisons. For the latter, more than 1,000 strains of P. pacificus and close to 50 Pristionchus species have been collected from around the world, providing material for natural variation studies (www.pristionchus.org). We use our field station on La Réunion, an island in the Indian Ocean that harbors the complete worldwide genetic diversity of P. pacificus, as microcosm for population level analysis of ecology and developmental plasticity.