Experimental crosses with genetic distance, divergence time and sample sizes.

Crosses with parental species names, geography (sym = sympatric, allo = allopatric), genetic distance (uncorrected p), and divergence times in million years based on the lower and upper bounds of an internally calibrated, linear clock (using the age of Lake Malawi [30]), and two relaxed non-linear molecular clocks using the cichlid fossil record and the break up of Gondwanaland [31]. For details on these calibrations see Stelkens et al. [12]. The number of families used for the calculation of the different fitness components are shown (fert = fertilization rate, hatch = hatching rate, 14 surv = survival rate until 14 days after hatching, 180 surv = survival rate until 180 days after hatching, cumul = cumulative fitness), and the number of F1 families used to produce F2 (“mixed” indicates one case where we were forced to merge several F1 families before generating F2). Homospecific, non-hybrid crosses are listed in the lower part of the table. Hyphens indicate missing data. The number of families available usually drops with developmental stage because mortality increases with each successive measurement. For some families fitness was measured at later stages but not at earlier stages or vice versa, which is why the number of families is not stable or does not always decrease as the experiment progressed.Experimental crosses with genetic distance, divergence time and sample sizes.