Statistical analyses of variation of initial fly sizes vs. the size of flies post-selection–all reared in normoxic conditions.

Repeated Measures ANOVA statistics (α = 0.05) for the starting populations at Generation 0 vs the second generation (Generation 13) of populations post-size selection and returned to normoxia. Although all these flies were reared in normoxia, the analyses compare previously hypoxic-selected (10 kPa, top) or previously hyperoxic-selected flies (40 kPa, bottom) to control flies that experienced size selection in normoxia (21 kPa). Significant p values are boldfaced. In general, flies were larger in generation 13 than in the starting populations, indicating evolution of larger size in response to truncation selection (significant generation effects). However, there were no significant effects of the aPO2 during the period of size selection. (F = F-ratio; DF = degrees of freedom).