Hybridization and introgression in Hill's oak (Quercus ellipsoidalis)

Oaks (Quercus: Fagaceae) are renowned for their taxonomic difficulties, and in fact they have been referred to as a "worst case scenario for the biological species concept" (Coyne and Orr 2004). Work in my lab focuses on a morphologically variable Great Lakes endemic, Hill's oak (Quercus ellipsoidalis E. J. Hill), which ranges from sandy soils in the northern portions of its range to silty and even calcareous soils in the greater Chicago region. The species is arguably the Midwest's most problematic member of the black oak section and is distinguished by the sheer number of workers who have puzzled over its taxonomic status and proper identification. In our published work, we have demonstrated that the species is taxonomically distinct from both black oak (Q. velutina Lam.) and scarlet oak (Q. coccinea Münchh.) but that there appears to be introgression between black oak and Hill's oak. We are currently investigating patterns of gene flow among these species using AFLP, microsatellite, and micromorphological characters.

This project has several components:

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