The importance and prevalence of recent ice-age and post-glacial speciation and species diversification during the Pleistocene across many organismal groups and physiographic settings are well established. However, the extent to which Pleistocene diversification can be attributed to climatic oscillations and their effects on distribution ranges and population structure remains debatable. In this study, we use morphologic, geographic and genetic (RADseq) data to document Pleistocene speciation and intra-specific diversification of the unifoliolate-leaved clade of Florida Lupinus, a small group of species largely restricted to inland and coastal sand ridges across the Florida peninsula and panhandle.
View Article and Find Full Text PDFThe evolution of secondary (insular) woodiness and the rapid disparification of plant growth forms associated with island radiations show intriguing parallels between oceanic islands and tropical alpine sky islands. However, the evolutionary significance of these phenomena remains poorly understood and the focus of debate. We explore the evolutionary dynamics of species diversification and trait disparification across evolutionary radiations in contrasting island systems compared with their nonisland relatives.
View Article and Find Full Text PDFPremise Of The Study: The Andean highlands are a hotspot of domestication, yet our understanding of the origins of early Andean agriculture remains fragmentary. Key questions of where, when, how many times, and from what progenitors many Andean crops were domesticated remain unanswered. The Andean lupine crop tarwi (Lupinus mutabilis) is a regionally important pulse crop with exceptionally high seed protein and oil content and is the focus of modern breeding efforts, but its origins remain obscure.
View Article and Find Full Text PDFThe evolutionary processes that drive rapid species diversification are poorly understood. In particular, it is unclear whether Darwinian adaptation or non-adaptive processes are the primary drivers of explosive species diversifications. Here we show that repeated rapid radiations within New World lupins (Lupinus, Leguminosae) were underpinned by a major increase in the frequency of adaptation acting on coding and regulatory changes genome-wide.
View Article and Find Full Text PDFAlpine plant radiations are compared across the world's major mountain ranges and shown to be overwhelmingly young and fast, largely confined to the Pliocene and Pleistocene, and some of them apparently in the early explosive phase of radiation. Accelerated diversification triggered by island-like ecological opportunities following the final phases of mountain uplift, and in many cases enabled by the key adaptation of perennial habit, provides a general model for alpine plant radiations. Accelerated growth form evolution facilitated by perenniality provides compelling evidence of ecological release and suggests striking parallels between island-like alpine, and especially tropicalpine radiations, and island radiations more generally.
View Article and Find Full Text PDF