Fig. 2

M. emersoni populations have adapted physiologically to the prevalent environmental conditions that were established after climate warming began 10,000 years BP. a Heat shock experiment: M. emersoni workers from warmer collection sites show significantly less mortality after a one hour heatshock at 50 ° C than workers from colder collection sites (R² = 0.42, p = 0.035), indicating that M. emersoni colonies are adapted to the local environmental conditions that were established after climatic warming. b Cold shock experiment: M. emersoni workers from colder collection sites show a significantly more rapid recovery after a 16h cold shock at 4 ° C than workers from warmer collection sites (R² = 0.46, p = 0.018)