PARENT SESSION
Oral Session #90: Evolutionary Ecology.
Presiding: R. del Castillo
Thursday, August 8. 1:00 PM to 3:45 PM. Apache Meeting Room, TCC.
Experimental evidence of local adaptation in a salamander-virus system.
Schock, Danna*,1, Collins, James1, 1 Arizona State University, Tempe, AZ
ABSTRACT- In systems where a pathogen and its host species have a large, heterogeneous range, the pathogen should be locally adapted to its native host population, producing regional disease dynamics in response to local selection pressures. We are testing these ideas using an amphibian-virus system. Tiger salamanders (Ambystoma tigrinum) are found across most of North America in habitats ranging from alpine meadows to prairie ponds. A complex of closely related ranaviruses is associated with tiger salamander die-offs from Saskatchewan, Canada to southern Arizona, USA. As part of an ongoing study, we conducted a common garden experiment exposing tiger salamanders from populations in central Saskatchewan, southwestern Manitoba, and northern Arizona to virus isolates from the same three areas in all possible combinations. As predicted by theory, virus isolates were most effective at evading their own host population defenses, indicating virus isolates are locally adapted. Further, the results of novel host-pathogen pairings were unpredictable and could not be inferred from knowledge of how the virus isolate performed in its native host population. Given the ever-increasing ease with which pathogens are moved on global scales, these findings have important implications for wildlife conservation and epidemiology.
KEY WORDS: amphibian, ranavirus, disease ecology