Fig. 2

The mean proportion of non-ecological barriers of Daphnia across the different cross categories: a mating-fertilization success, b F1 zygotic mortality, c F1 hatching success, and d F1 survivorship. Each cross category is symbolized as: conspecific Daphnia pulex (px x px) and Daphnia pulicaria (pc x pc), divided into intrapopulation (I), geographically close (C) and geographically far (F) categories; and heterospecific D. pulex female x D. pulicaria male (px x pc) and its reciprocal cross, D. pulicaria female x D. pulex male (pc x px) divided into allopatric (A) and sympatric (S) groups. Each cross category is plotted with their respective (±) standard errors. In asterisks (*) show significance (p < 0.05) between the different groups (shown in bars) based on post-hoc Tukey test