Evolution of Communication Systems:
Some of the big questions in animal communication include: Which signals are used? How are signals produced and received? How did signals evolve? How is the evolution of signals shaped by senders, intended receivers, the physical environment? And how do unintended receivers such as individuals from different species, parasites or predators influence signal exchange among potential mates? These questions are addressed in our lab using fireflies (Lampyridae, Coleoptera) as a model system. We are using phylogeny-based approaches to study the evolution of signal phenotypes and the production and reception of light signals under different environmental conditions (habitat characteristics, other signaling species and predators). We are also working on sensor evolution, aposematic signaling, and the biogeography of fireflies.
Signal Evolution in Lampyridae (fireflies or lightningbugs)
Our lab is using molecular data to elucidate the phylogenetic relationships of lampyrids (Coleoptera), with a special emphasis on the ~150 species present in North America. We are currently extending this work to fireflies worldwide. The firefly system is exceptionally well suited as a study system, because it allows us to connect signal phenotypes with the underlying genes and their molecular evolution. Our lab has extensive field experience in firefly behavior, light emission measurements, sensor morphology, molecular methods and phylogenetics.
1. Worldwide phylogeny of fireflies and evolution of signal mode. In collaboration with Seth Bybee (Brigham Young University) and Marc Branham (University of Florida) we are generating a world-wide genus-level firefly phylogeny to study signal evolution (light signals, pheromones) and associated sensor morphology in this beetle family.
2. Species-level phylogenies of fireflies and signal evolution. In collaboration with Dave Hall (University of Georgia) we utilized firefly genomes and transcriptomes to generate a probeset (500 probes) for Anchored Hybrid Enrichment as a basis for the worldwide phylogeny. We are also using them to generate robust species-level phylogenies to test hypotheses on selection and address communication-related questions in the visual communication system of fireflies. These phylogenies serve as a tool to investigate signal evolution (pheromones, flashes, glows) in this group, including the influences of natural and sexual selection on the evolution of the diverse flash patterns and light color among North American fireflies. In addition, we are doing fieldwork to investigate how individual firefly communities divide up the signaling space between species to reduce mistakes in species identification and mate choice, and how they protect themselves from predators.
3. Signal production and reception. We are sequencing genes involved in light production (luciferase) and reception (opsins) to examine whether selection acts on signal production and reception in fireflies. In addition, we are doing fieldwork (ambient light measurements in different habitats and measurements of firefly light spectra) and gene expression studies to investigate the light color evolution in fireflies.
4. Biogeography of fireflies. In collaboration with Jim Lloyd (University of Florida) we are investigating the biogeography of North American fireflies. The species-distributions of the ~150 North American (NA) firefly species differ widely in location and area. Our research will identify physical (elevation, precipitation and temperature, vegetation cover, etc.) and biological (congeners, other firefly genera, firefly predators, etc.) variables that best explain the biogeography of NA fireflies.