Many SDSU Biology graduate students have, or are currently conducting, specimen-based research. Our students advance the study of regional binational ecosystems and their organisms, through excellence in data-driven research and analysis of evolutionary processes from the molecular to continental scales.
Current Museum Graduate Student Projects
Alyssa Head (Brock Lab), Morphological and genetic shifts in an expanding population of a globally introduced species, the Italian wall lizard (Podarcis siculus). Alyssa is interested in how genetic variation and functional morphology contribute to the success of introduced species in novel environments and she is currently comparing historical and contemporary specimens of introduced wall lizards in Los Angeles to their relatives back in Taormina, Italy.
Danielle Parsons, Floristics of Palomar College Native and Naturalized Plants. Danielle is documenting the native and naturalized plants of properties east of Palomar College, with both iNaturalist observations and herbarium voucher specimens. See Palomar College Native & Naturalized Plants.
Michael Tofflemire (Burns Lab), Comparative Phylogeography of Birds in the California Floristic Province. Michael is using genetic samples of specimens in our museum to study the comparative phylogeography of four co-distributed species in California (Wrentit, California Thrasher, White-headed Woodpecker, and Mountain Chickadee). By studying multiple species, he will be able to address whether all species responded in the same way to the same biogeographic events. That is, what is the historical pattern of community structure? Have some species co-existed in the same community and habitat longer than others? Are some species more likely to undergo range expansions and habitat shifts?
Amber Singh (Brock Lab), Lizard SCUE: Stress Cognition, and Urban Evolution. Amber is studying how urbanization and stress influence cognition and behavior in co-occurring lizard species in southern California: native Western Fence Lizards (Sceloporus occidentalis) and introduced Italian Wall Lizards (Podarcis siculus). In addition to contributing hundreds of new whole specimens and tissues to the Reptiles and Amphibians collection through her research, Amber is also working to improve the collection by transferring older specimens into fresh ethanol for long-term preservation.
Tucker Heptinstall (Brock Lab), City Serpents: Exploring Snake Evolution in Modern and Ancient Cities. Tucker’s research is focused on how urban infrastructure like roads and housing developments influences the presence, abundance, movement, and gene flow of snakes in new and ancient cities. Tucker is contributing whole snake specimens and tissues from new city habitats across San Diego County and hundreds of snake tissues from ancient cities in the Greek archipelago. He is using these tissues to analyze population dynamics and gene flow in the face of long and short-term urbanization.
Sam Wilson (Brock Lab), Changing Landscapes Changing Tactics: The Impact of Novel Environments on Gecko Defense Strategies. Sam is studying convergent morphology-behavior relationships in geckos in their native range in the Mediterranean (Patras, Greece) and introduced range in southern California (San Diego). Sam is using museum specimens to create 3D gecko models deployed in urban and non-urban settings to quantify predation rates. He’s also contributing gecko tissues and whole specimens to the Reptiles and Amphibians collection.
Ian Ashton (Hedin Lab), Possible de-speciation in Habronattus jumping spiders. Ian is studying multiple parallel jumping spider hybrid zones to understand if color preferences are driving unidirectional introgression, such that a broad-ranging species is introgressing into a more narrowly-distributed species, causing the latter to go extinct. Ian’s work combines fieldwork, morphological study, and subgenomics.
Harshita Vallabhaneni, Elisa Paider (Clark Lab), Comparison of Rattle Morphology Throughout the History of San Diego County. Harshita and Elisa are interested in understanding if an increase in urbanization in San Diego County over the past century has driven changes in the growth and size of resident Southern Pacific and Red Diamond rattlesnakes. Rattlesnakes create a new segment at the base of the rattle every time they shed their skin, and the width of the new segment is directly correlated to the body size of the snake at the time it sheds; thus, widths of rattle segments can be used to understand relative changes in growth and body size within and between species. Their research utilizes specimens from our museum, as well as the San Diego Natural History Museum, comparing historical data (pre-1950) to contemporary data collected from snakes that still reside in these same areas that are now heavily urbanized.
Allie Tappe (Burns Lab) Leveraging Geographic Plumage Variation to Elucidate Relationships among Climate, Genotype, and Phenotype: A Comparative Approach. For her MS thesis, Allie is using tissues from our museum to sequencing genomes of the California Thrasher. She is using these data to study the phylogeographic history of this species to learn how the species has responded to past geological and climatic events. She is taking a comparative approach, comparing her data to the co-distributed Wrentit. In addition, she is quantifying color variation in both species, looking for correlations between phenotypic, genotype, and the environment.
Jadon Gonzales (Hedin Lab), Revisionary Systematics & Biogeography of Yorima spiders in California. Jadon is combining a large collection of morphology- and genomics-preserved SDSU Museum samples with original fieldwork. He has already discovered several undescribed species in this collection, which he is investigating using a combination of morphological examination and subgenomic data. Ultimately he intends to reconstruct a phylogeny for this radiation of California endemic taxa, and use this phylogeny as a basis for a taxonomic revision, and to understand the historical biogeography of the group.