One of the most compelling applications of determining evolutionary relationships is to explain the evolution of complex behaviors. Spider wasps exhibit a variety of behaviors associated with nesting for which evolutionary scenarios have been postulated in the past, but never tested. Specific objectives of this project are to reconstruct and revise the higher-level classification of spider wasps, to propose new scenarios for how nesting behaviors may have evolved, and to maintain a website that organizes information on the project. Evolutionary relationships and relatedness will be estimated from morphological, behavioral, and molecular data.
The results are likely to challenge existing paradigms concerning the evolution of social behaviors in general, as well as wasp nesting specifically, which will likely lend scientific rigor to, or revise, information presented in college textbooks. This study also is important because it will train undergraduate and graduate students in morphological and molecular methods, and will help transfer taxonomic information from a retired expert to younger generations of systematists. The project will also result in products that will be accessible to non-experts. The interactive keys produced will enable non-experts to identify spider wasps, while the website will be approachable to non-experts and will be a useful teaching tool from the high school to professional levels
The specific goals of the project were to determine evolutionary relationships of spider wasps using morphological data, molecular data from multiple genes, and behavioral data. From the resulting evolutionary relationships, we were to propose new evolutionary hypotheses concerning the steps by which behaviors associated with nesting, such as the type of nest used, the mode of transporting the host to nest, nest construction, etc., evolved. Lastly, we were to prepare a classification system that reflects the relationships that we uncovered. Our findings suggests that the previous classification of spider wasps is incorrect, and using our classification provides a better understanding of how nesting behaviors evolve in this group of wasp. For instance, dragging the host while walking backwards--a behavior that scientists term as simple because the spider wasp does not see where sit is going--can evolve from draggin the host forward, which is considered more complex. This research is applicable to the study of behavioral evolution in general suggesting that behavior does not necessarily evolve in a stair-step fashion and simple behaviors can evolve from complex behaviors, and very complex behaviors can evolve from simple ones with out the need for an intermediate behavioral state. Additionally, our research suggest that these wasps were able to disperse between continents, and the historical dates of these events agree with some, but not all, of those proposed for other organisms.
