Figure 2: Lower introgression at sex-linked compared to autosomal markers.
From: Empirical evidence for large X-effects in animals with undifferentiated sex chromosomes
(a) Sex-linked (red squares) and autosomal (black circles) hybrid indices (0: pure H. orientalis, 1: pure H. arborea) for each individual compared to their HI over all markers. Solid lines are maximum likelihood fits of the data to Fitzpatrick’s genome cline model51. Squares show sex-linked and circles autosomal markers. The data is significantly better explained by introducing a separate (steeper) cline for the sex-linked loci (Gtest ΔLL = 4.07, df = 2, P = 0.0003; see Results). (b) Comparison between sex-linked and autosomal introgression in 32 confirmed hybrids (see Methods); the difference is strongly significant (paired non-parametric Wilcoxon test, p = 4.0 e−6). Photo of H. orientalis: Matthias Stöck; photo of H. arborea: Amaël Borzée.
