Data from: The ecology of hybrid incompatibilities

Ecologically-mediated selection against hybrids, caused by hybrid
phenotypes fitting poorly into available niches, is typically viewed as
distinct from selection caused by epistatic Dobzhansky-Muller hybrid
incompatibilities. Here, we illustrate how selection against transgressive
phenotypes in hybrids manifests as incompatibility.  After
outlining our logic, we summarize current approaches for studying
ecology-based selection on hybrids. We then quantitatively review
QTL-mapping studies and find traits differing between parent taxa are
typically polygenic. Next, we describe how verbal models of selection on
hybrids translate to phenotypic and genetic fitness landscapes,
highlighting emerging approaches for detecting polygenic
incompatibilities. Finally, in a synthesis of published data, we report
that trait transgression—and thus possibly extrinsic hybrid
incompatibility—in hybrids escalates with the phenotypic divergence
between parents. We discuss conceptual implications and conclude that
studying the ecological basis of hybrid incompatibility will facilitate
new discoveries about mechanisms of speciation.