Elizabeth Stacy and Tomoko Sakishima (both Life Sciences) have written a paper with coauthors Neil Snow of Pittsburgh State University and Heaven Tharp, an undergraduate student at the University of Hawaii, that recently was accepted for publication in the Journal of Heredity's Symposium Issue, "Origins of Adaptive Radiation." This issue features research presented by invitation at the American Genetics Association President's Symposium in 2018. The paper, "Isolation of Metrosideros (`Ohi`a) taxa on O`ahu Increases with Elevation and Extreme Environments," presents a key for the identification of 12 taxa of the landscape-dominant woody species complex on O`ahu, demonstrates heritability of the morphological characters used to distinguish these taxa, reports the narrow partitioning of the island's elevation gradient by these taxa, and reports an increase in genetic isolation of taxa with elevation or otherwise extreme environments. These results suggest that differential local adaptation across heterogeneous environments can drive diversification within continuously distributed populations of long-lived species over surprisingly small spatial scales. Sakishima is a Ph.D. candidate.