Meeting Abstract
Measuring the physiological consequences of discrete evolutionary adaptations is a critical component to predicting ecological responses. While adaptations may be overall beneficial to an animal, there may be unknown costs. To adequately understand potential trade-offs associated with discrete physiological adaptations, we must measure the true costs of these adaptations. To accomplish this, we utilized a well-known model of co-evolution: the resistance of the natural toxin tetrodotoxin (TTX) by gartersnakes that are sympatric with TTX-secreting newts, a prey item. Gartersnakes that have evolved outside the range of these newts have not evolved this resistance, making a contrast between individuals with high and low resistance possible. We measured individual resistance to TTX in snakes from a resistant population from Benton County, OR and a non-resistant population from Cache County, UT by determining the dose that reduced racing speed by 50%. To assess the potential trade-offs involved with evolving this resistance, we determined the efficacy of the stress and immune responses in these individuals by quantifying corticosterone (CORT) and bactericidal ability. By correlating these important life-history functions to a measurable adaptation such as resistance to a natural toxin, we can better understand the role of physiological processes in evolution.
