Figure 1.

age-1(hx546) mutants have higher fitness than the wild-type genotype if periodically exposed to intense thermal stress when food is available. Temporal changes in frequencies of the age-1(hx546) allele, relative to the wild-type age-1(+) allele, in populations with unlimited (solid lines) and limited (broken lines) food which were (A) maintained at 20°C, (B) periodically exposed to 27°C, or (C) periodically exposed to 30°C. Arrows indicate days on which 24 h thermal stress treatments (27°C or 30°C) were implemented. Data are presented from two separate experimental blocks in which four replicate populations were exposed to each treatment.