I am interested in the description and analysis of biological patterns. The primary focus of my published research has been morphometric studies of ciliated protists, especially the genus Euplotes, aimed at resolving evolutionary and systematic problems. A secondary interest is in studying these single-celled, eukaryotic, heterotrophic, sexually reproducing organisms from the perspectives of population biology, e.g., to assess the genetic differentiation of populations and the functioning of aquatic ecosystems. Almost all of my scientific papers have involved the analysis of quantitative, multivariate data, usually by statistical means.
Ciliates such as Euplotes are rigid, dorso-ventrally flattened cells that are adorned with distinctive organelles, composed of cilia, that are specialized for locomotion and for feeding upon smaller microorganisms. These ciliary structures are precisely positioned during the morphogenetic events of cell division, resulting in distinct patterns of linear ciliary rows on the dorsal surface and very different, clustered patterns of large, compound ciliary structures on the ventral surface: the locomotory cirri and the feeding membranelles.
By using silver-staining techniques and a computerized digitizing apparatus, the coordinate positions of these structures can be mapped in numerous individual cells representing clones derived from different natural populations of one or more species, sampled from various geographic areas and subjected to appropriate experimental conditions. For example, the analysis of variations in quantitative measures of the abstract patterns of cirral placement on the ventral surface can be used to study the processes of population differentiation in structural attributes and these then can be interpreted to resolve taxonomic problems. Similarly, the stability of morphological structural patterns can be ascertained under different experimental conditions.
My current research with these fascinating organisms involves three additional projects:
- determination of the effects of temperature on two key aspects of organismal performance - locomotory speed on solid substrates and strength of mating interactions ["hypotrich" ciliates such as Euplotes have numerous mating types, or "sexes"];
- a collaborative survey of genetic variation in rDNA genes in Euplotes species; and
- a collaborative survey of variations in the production of sesquiterpene defensive compounds called euplotins in different natural populations of various marine species of Euplotes.