The desert genus Encelia has long been a model system in plant ecophysiological studies because of its high phenotypic diversity. In a recently accepted paper, we combine a reciprocal transplant with fine-scale physiological measurements and genomic analyses to show how Encelia may represent a novel system for studying evolution, as well.
This paper has been a decade in the making and has undergone multiple complete rewrites that have integrated completely new datasets. In it, we show how phenotypically divergent species that undergo frequent hybridization can nonetheless remain genetically distinct because of strong natural selection. Importantly, natural selection results from multiple, coincident, and concordant environmental axes.
Combining anatomical, physiological, genomic, and ecological data together show how an integrative approach to studying biological systems can more fully elucidate how natural selection acts on phenotypes and impacts gene flow.
The preprint is available here, and it is currently accepted at PNAS.