Given that I’d just spent months bent over a table picking tiny teeth out of piles of dirt and rock, I was not eager to repeat that experience. But I did! I sorted through bones for another site on Stanford lands by hand. Luckily, I didn’t have to collect all my archaeological evidence from scratch. For the rest, I turned to the scientific literature — the body of articles that scientists publish about their research. These articles preserve information for the future just as Barbara Bocek and Liz preserved physical evidence. The data from scientific papers can function the same way, recording data for others (like me) to use. I now focused my attention on the computer screen, mining the literature for usable data. I searched for archaeological sites in the Bay Area that had published small mammal data.
The archaeological data made clear the outsized impact of recent human activity on San Francisco Bay Area small mammal communities today. Small mammal communities reconstructed from archaeological sites were more similar to each other regardless of geographic proximity to modern sites and vice versa. For example, the Jasper Ridge archaeological site is right next door to the Jasper Ridge pellet collection sites — but their reconstructed small mammal communities (ancient and modern respectively) aren’t the same. The Jasper Ridge archaeological animal assemblage is more similar to other ancient assemblages, while the modern Jasper sites are more like other modern assemblages. This suggests that location is much less important in determining what small mammals live in a place than is time — i.e., whether the mammals lived thousands of years ago, alongside native human communities, or today, alongside present-day cities and suburbs.
My data also challenge an assumption made by some ecological studies — that the ecology of seemingly pristine habitats today represents their ecology as it was thousands of years ago. What I’m finding suggests otherwise: even protected spaces are deeply affected by human impacts. For example, even “pristine” sites in the U.S. will likely include invasive species that were not present until the arrival of Europeans. All my modern sites, including the protected Jasper Ridge, contained European rats (in the genus Rattus) which stowed away on boats and were thereby inadvertently introduced to the Americas.
But that does not mean that there is no point in trying to protect areas from human impacts. My preliminary results also suggest that the less disturbed a modern site was, the more similar its ecosystem was to its past state. Human activity today does change everything, but not equally. Protected areas seem to be affected less.
With this research, I hope to contribute to our understanding of how small mammal communities have been impacted by humans in recent history. But I’m not there quite yet. I am still collecting and analyzing data for this project, including adding new evidence from an additional archaeological site on Stanford campus. And as I collect these data, I will preserve them for future generations of scientists, just as others did for me, to study using techniques we’ve not yet developed and to answer questions we’ve not yet thought to ask.
I would like to thank Liz Hadly, my dissertation committee, and all the members of the Hadly Lab for their guidance. I’d also like to thank the staff of Stanford University Archaeology Collections and Jasper Ridge Biological Preserve for their support. Thanks also to the students and community members who contributed to this project: Mahpiya Vanderbuilt, Carson Conley, Liraz Bistritz, Kate Recinos, and Targe Lindsay. Finally, I’d like to thank Stanford Biology, the Paleontological Society, and the National Science Foundation for funding my research.
In addition, I acknowledge that Stanford and Jasper Ridge Biological Preserve sit on the ancestral and unceded land of the Muwekma Ohlone Tribe. This land was and continues to be of great importance to the Ohlone people. Consistent with Stanford’s values of community and diversity, we have a responsibility to honor and make visible the university’s relationship to Native peoples. More information about the Muwekma Ohlone Tribe can be found here: http://www.muwekma.org/.