The TFT-bearing BRO haplotype and the putatively healthy DAH haplotype were introgressed into the outbred nuclear background Dahomey in three independent replicates (i.e. BRO:Dahomey1-3; DAH:Dahomey1-3). Experimental populations were established by supplementing DAH:Dahomey test populations (DAH:Dahomey1-3) with varying contributions of fly pairs bearing the TFT haplotype (0%, 25%, 50%, 75%) sourced from the corresponding BRO:Dahomey replicate population (i.e. DAH:Dahomey1/BRO:Dahomey1; DAH:Dahomey2/BRO:Dahomey2; DAH:Dahomey3/BRO:Dahomey3). For each of the three biological replicates and for each treatment class (0%, 25%, 50%, 75%), we established seven technical replicate populations. These experimental populations were further duplicated, one cohort providing populations for the regulated population size approach (Experiment 1), and one cohort for the fluctuating population size approach (Experiment 2).