Journal Article Quercus introgression California Research Support, Non-U.S. Gov't genetic admixture hybridization Anthropocene Congress Fagaceae Research Support, U.S. Gov't, Non-P.H.S. comparative biogeography ddRAD-seq diversification rates ecosystem services environmental disturbance environmental variation genetic structure genomic mosaicism genomic sequence and structure oak oaks phenotypic response phylogenomics restriction-site associated DNA sequencing (RAD-seq) tree diversity wildfire