In 1988 I visited the laboratory of Alan Wilson. PCR had been developed three years earlier, but mitochondrial primers were only then being developed. I brought DNA from periodical cicadas with me. In the Wilson lab, I amplified this cicada DNA with primers developed for human mtDNA. Ironically, these unusual insects, not Drosophila, were the first insects to be amplified by PCR.

I was invited to write a review article on insect molecular systematics for the Annals of the Entomological Society of America and, at the same time, Crespi had approached me to collaborate on a mitochondrial PCR primer compilation. Many of these primers had been developed in the lab of Beckenbach. The paper thus originated as a discussion among colleagues. Two of the other authors were postdocs in the Simon lab and one was a former postdoc in the Beckenbach lab.

It provided a condensed guide to molecular systematics problems and applications. The review of the properties of molecular systematic data was applicable to all fields. The primer compilation appendix provided a standardized, informative naming system for PCR primers via which the location of the primer and the size of the expected product could be easily determined. The primer compilation was applicable to all animals, not just insects.

Over the last 10 years the Simon lab has produced a series of publications focusing on how knowledge of molecular processes can improve phylogenetic analysis. Of particular to interest to us has been how variation in the rate of molecular evolution among sites in a DNA sequence can be accommodated in phylogenetic analysis. Several papers focusing on the analysis of the structure of rRNA molecules contributed to the understanding of rate variation among sites and helped to evaluate current DNA alignment procedures. In addition, the Simon lab focused on the molecular systematics and biodiversity of insects, especially cicadas.

Currently, rapid progress is being made by the Simon laboratory in producing generic and species-level molecular phylogenies for New Zealand cicadas and representatives of their tribe worldwide. Mating-signal evolution is being studied by mapping male song characteristics onto phylogenetic trees. Much of this research has general importance to studies of speciation, sexual selection, and evolution in general. In collaboration with NZ colleagues, the Simon lab is studying 19 contact zones between NZ cicada species of different degrees of relatedness. Microsatellite data and songs against a backdrop of an mtDNA phylogeny are being used to search for evidence of gene flow between species. Similar work on speciation, but in relation to life history and song variation, is being pursued using the North American cicada genus Magicicada.

The longer-term goals of the Simon lab are to finish the description of all NZ and Australian cicada species, to construct phylogenetic relationships for all world genera and selected species groups that are tied to interesting evolutionary questions, and to revise the tribes and subfamilies of cicadas worldwide. Also of interest is to use these phylogenies and molecular dating techniques to recreate the Mesozoic and Cenozoic biogeography of the group. The Simon lab is part of a larger group of principal investigators studying Paraneoptera (lice, thrips, plant-sucking bugs, and true bugs). This group is part of a worldwide effort to construct a "Tree of Life" phylogeny for all organisms. Such a tree would accelerate the rate at which progress could be made in studying all aspects of biological evolution.

It is critically important to know the natural history of your study subject. This principle applies to DNA as well as to whole organisms. By understanding the way in which genes evolve, function, and are structured, it is possible to gain insights that can be used in improving the way that evolutionary trees (phylogenies) are constructed from DNA data. It is important to look at your data and to think carefully how it is analyzed. Similarly, to study evolution, it is important to understand the biology and life history of species under study, sample multiple individuals per species, and survey genetic variation over geography.

Dr. Chris Simon
University of Connecticut
Storrs, CN, USA