Table 2. Pairwise comparisons (Tukey HSD test) from a linear model show that in mel/san hybrids, only chromosome two is marginally affected by temperature, and the effect size is modest.

Linear Hypothesis	Mean 1	Mean 2	Estimate	SE	t Value	P-value
X.sim.24° − X.sim.18° == 0	0.4975	0.4465	0.0402	0.0286	1.407	0.9612
2.sim.24° − 2.sim.18° == 0	0.5278	0.4964	0.0314	0.0206	1.524	0.9323
3.sim.24° − 3.sim.18° == 0	0.4986	0.4917	0.0068	0.0244	0.279	1.0000
X.san.24° − X.san.18° == 0	0.4014	0.5377	0.0451	0.0286	1.579	0.9144
2.san.24° − 2.san.18° == 0	0.4430	0.5027	−0.0598	0.0206	−2.901	0.1399
3.san.24° − 3.san.18° == 0	0.4113	0.4229	−0.0116	0.0244	−0.475	1.0000

The first column shows the pairwise comparisons (Chromosome.Species.Temperature). Mean 1 refers to the mean of the first category listed in the comparison; Mean 2 refers to the mean of the second category. The effect of temperature was not significant in either mel/sim or mel/san hybrids. P-value, ; mel, D. melanogaster; san, D. santomea; sim, D. simulans.