Danville resident, Hamilton College junior Maddie Vavra studyng the keyhole limpet sea snail
Vavra is a biology major at Hamilton
Clinton, NY (01/07/2022) — Danville resident Maddie Vavra, a junior biology major at Hamilton College, has spent the last year conducting marine biology research, studying keyhole limpets, a form of sea snail. Part of the Diodora genus, these snails sit at the base of the main branch of the gastropod (snail) tree of life. As such, they provided an interesting perspective for tracking snail evolution, said Biology professor Patrick Reynolds, who oversaw the student research.
Vavra, along with several senior thesis students, began their research last January. At the time, their goal was to perform species identification for the keyhole limpet specimens that Reynolds had acquired through the Florida Museum of Natural History (FMNH). The specimens had been preliminarily identified based on their morphology, or physical traits, but the students had to confirm these identifications genetically through a process known as DNA barcoding. In doing so, they also retrieved genetic data necessary to create a well-supported phylogeny, or hypothesis for the evolutionary relationship among the species.
While other papers have been published on Diodora phylogeny, the FMNH's collection of keyhole limpets spanned a wide geographical range - from the Red Sea to Hawaii and all the way to Australia and Singapore. In fact, the collection included species from the Pacific and Indian oceans that have yet to be featured in published research, Reynolds said.
Last spring, the students successfully identified 55 of the 70 specimens sent by the FMNH. Vavra and another student continued the work this fall on the remaining 15 unidentified specimens. They focused on adjusting the conditions for PCR (polymerase chain reaction) since this step was determined to be key in successful identification. By looking at scientific literature, the pair and Reynolds found that a higher PCR temperature resulted in greater success for some species.
The increase in temperature did yield better results. However, despite having strong DNA sequences for the specimens, there were still some that didn't match strongly with any other specimens on GenBank, the National Institute of Health genetic sequence database.
"This means there's a good chance that the species isn't in GenBank, which is pretty cool," Vavra said. "It means we're either looking at a very rare, understudied species or possibly even an undiscovered species, though that's less likely."
Ultimately, the DNA data retrieved from the specimens suggest that previous hypotheses published on the evolutionary tree of Diodora may be incorrect, Reynolds said, though more work still needs to be done.
Maddie Vavra is a graduate of Monte Vista High School
Originally founded in 1793 as the Hamilton-Oneida Academy, Hamilton College offers an open curriculum that gives students the freedom to shape their own liberal arts education within a research- and writing-intensive framework. Hamilton enrolls 1,850 students from 49 states and 46 countries. Additional information about the college can be found at www.hamilton.edu.
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