Stephanie Bartlett, Utah Valley University
Life Sciences
Our project investigates the phylogenetic relationships of the superfamily Ephemeroidea + Behningiidae. Found in waters worldwide, burrowing families are unique in that they have mandibular tusks that allow them to tunnel in the silt or gravel of riverbeds. Surprisingly, even without the mandibular tusks necessary for tunnel construction, the Behningiidae family is still found within these burrows as nymphs. Because the Behningiidae don’t have tusks, morphological research has lead to a phylogenetic classification of this family that our genomic investigation ultimately disputes. To begin this investigation, mayfly specimens were collected worldwide and prepared for DNA extraction. For each specimen genes were amplified via polymerase chain reaction and visualized on an agarose gel, before being sequenced and analyzed. The specific genes targeted for this analysis include; 12s mitochondrial rDNA, 16s mitochondrial rDNA, 18s nuclear rDNA, 28s nuclear rDNA, H3 nuclear protein coding, and CO1 mitochondrial protein coding. Datasets were supplemented with sequences acquired from Genbank. The ingroup consisted of approximately 30 samples. Phylogenetic relationships were estimated using Maximum Parsimony, Maximum Likelihood, and Baysian methods. We constructed phylogenetic relationships of burrowing mayflies using molecular DNA data analysis, when compared to morphological analysis we identified some important classification differences. As a result of our findings, we propose an alternative explanation for the evolution of mandibular tusks in burrowing mayflies (Ephemeroptera). The data support that burrowing mayflies first evolved tusks. Within the family Behningiidae, tusks were lost, while the burrowing lifestyle (i.e., living in a burrow to filter feed) was retained. This study represents the largest analysis to date for these insects and strongly supports the evolutionary trend of a gain and a loss of mandibular tusks during their evolution.