Alaska Stable Isotope Facility seminars

February 28, 2018

University Relations

The Alaska Stable Isotope Facility will present two seminars at 1:30 p.m., March 6 and 7, in the  BP Design Theater, room 401 in the Engineering, Learning and Innovation Facility.

Tuesday, March 6, 1:30 p.m.

• "There and back again: Strontium isotopes provide insight into landscape use and migration of mammoths, mastodons, caribou, and other adventurers": A joint talk by Josh Miller and Abby Kelly, University of Cincinnati. Strontium isotope ratios (87Sr/86Sr) of bone and other animal tissues reflect resources available during tissue formation, which are strongly influenced by local geology. Using predictive regional models of Sr isotope ratios, it is now possible to evaluate the past mobility and migratory patterns of terrestrial faunas. Such data provide unique insight into new areas of paleoecology and historical ecology; including geographic partitioning of populations and species, changes in landscape use through ontogeny, and the impacts of climate and other ecological stressors on migration and dispersal. These dynamics in North American Pleistocene proboscideans and more contemporary Alaskan caribou from the Arctic National Wildlife Refuge are explored.


•  "Eastern Beringian bison diet and paleoecology over the last 50,000 years": How does a species adapt to ecological and climatic change? The late Quaternary of Beringia is an ideal system for studying long-term species responses to environmental change because it (i) experienced significant vegetation and climatic shifts over the last 50,000 years, and (ii) hosts fossil-rich permafrost deposits that record ecological responses with unusually high temporal resolution. This talk will explore the context of megaherbivore — vegetation interactions and detail methods for quantifying bison dietary shifts in Pleistocene-Holocene Beringia.

Wednesday, March 7, 1:30 p.m. 

• "Clarifying Mammalian Responses to Climate Change and Megafaunal Extinctions During the Pleistocene," presented by Larisa DeSantis, Vanderbilt University. Through the integration of multiple paleoecological proxies, my research clarifies: 1) how past climate change has affected mammalian communities and their floral environments; and, 2) how we can improve our understanding of the paleoecology and paleobiology of mammals through the integration of ecological, macroecological, geochemical, dental microwear, and morphological analyses. By continually integrating the fields of ecology and evolution, I use the fossil record to conduct deep-time experiments, revealing the causes and consequences of climate change and competition with novel predators (e.g., humans). With a focus on the late Pleistocene, I will discuss ways in which mammals have responded to changing climates in both North America and Australia.  Results question the assumption that dietary niches are conserved over time and instead demonstrate dramatic dietary responses to increased aridity. In Australia, increased competition for similar plant resources may have stressed the extinct megafauna and contributed to their eventual extinction. Collectively, paleoecological data here reveals the importance of the fossil record in clarifying mammalian responses to climate change and cautionary lessons of relevance to modern conservation.

For more information email mjwooller@alaska.edu.