Fig. 3.

Comparison of a) differential gene expression and b) hybrid gene misexpression among recent radiations and San Salvador pupfishes. a) The percentage of differentially expressed gene transcripts ranges from 1% to 30% among recent radiations, but the San Salvador trophic specialists with novel traits (blue, green, and pink triangles) do not stand out. b) Few studies have examined hybrid gene misexpression in non-model systems; however, molluscivore×generalist F1 hybrids exhibit substantial gene misexpression in their craniofacial tissues, including their unique nasal protrusion (green circle), relative to lake whitefish F1 hybrids (yellow triangle; but not F2 whitefish hybrids (orange triangle) which may be expected to exhibit transgressive expression patterns). Data from McGirr and Martin (2017, 2019); Jones et al. (2012); Ahi et al. (2014); Renaut et al. (2009); and Manousaki et al. (2013).