Event Category

PhD Appraisal

Date

July 15, 2026

Time

11:30 am

Location

Ramsay Wright Laboratories, RW 432

Anthropogenic stressors pose an unprecedented threat to biodiversity globally, and rising temperatures range among the greatest of those threats. As a result, it is imperative to use reliable, informed metrics to assess organismal responses to extreme temperatures (such as adaptation, acclimation, and survival)—especially for ectotherms, which comprise more than 99 per cent of extant species.

While many common assays are inherently one-dimensional, describing thermal tolerance as either a function of exposure time or temperature alone, the Thermal Death Time (TDT) framework comprehensively describes the strong log-linear relationship between a “stressful” temperature and an organism’s time to failure at that constant temperature. The TDT framework has increased in popularity in recent years due to its biological interpretability and inferential power in areas such as evolution, physiology, and climate biology. However, many of its details remain unstandardized, poorly characterized, and even statistically invalid.

Bullard’s thesis aims to improve TDT methodology and interpretation, drawing on physiological and statistical principles to create a more informed, accessible, and general framework to help broadly improve our ability to assess, predict, and interpret stress responses across disciplines, with applied implications for thermal and salt tolerance.

Supervisor: Don Jackson

Committee chair: Marty Krkosek