Plant evolution

Diversification of Genes Encoding Granule-Bound Starch Synthase in Monocots and Dicots Is Marked by Multiple Genome-Wide Duplication Events

by Awais Khan

Starch is one of the major components of cereals, tubers, and fruits. Genes encoding granule-bound starch synthase... more Starch is one of the major components of cereals, tubers, and fruits. Genes encoding granule-bound starch synthase (GBSS), which is responsible for amylose synthesis, have
been extensively studied in cereals but little is known about them in fruits. Due to their low copy gene number, GBSS genes have been used to study plant phylogenetic and evolutionary relationships. In this study, GBSS genes have been isolated and characterized in three fruit trees, including apple, peach, and orange. Moreover, a comprehensive

The evolution of land plants inferred using domains DF of the largest subunit of RNA polymerase II.

by Banoo Malik

Progressive Cenozoic cooling and the demise of Antarctica's last refugium

by Alexandra Kirshner

The Antarctic Peninsula is considered to be the last region of
Antarctica to have been fully glaciated as a... more The Antarctic Peninsula is considered to be the last region of
Antarctica to have been fully glaciated as a result of Cenozoic
climatic cooling. As such, it was likely the last refugium for plants and animals that had inhabited the continent since it separated from the Gondwana supercontinent. Drill cores and seismic data acquired during two cruises (SHALDRIL I and II) in the northernmost Peninsula region yield a record that, when combined with existing data, indicates progressive cooling and associated changes in terrestrial vegetation over the course of the past 37 million years. Mountain glaciation began in the latest Eocene (approximately 37–34 Ma), contemporaneous with glaciation elsewhere on the continent and a reduction in atmospheric CO2 concentrations. This climate cooling was accompanied by a decrease in diversity of the angiosperm-dominated vegetation that inhabited the northern peninsula during the Eocene. A mosaic of southern beech and conifer-
dominated woodlands and tundra continued to occupy the
region during the Oligocene (approximately 34–23 Ma). By the middle Miocene (approximately 16–11.6 Ma), localized pockets of limited tundra still existed at least until 12.8 Ma. The transition from temperate, alpine glaciation to a dynamic, polythermal ice sheet took place during the middle Miocene. The northernmost Peninsula was overridden by an ice sheet in the early Pliocene (approximately 5.3–3.6 Ma). The long cooling history of the peninsula is consistent with the extended timescales of tectonic evolution of the Antarctic margin, involving the opening of ocean passageways and associated
establishment of circumpolar circulation.

Lythrum and Peplis from the Late Cretaceous and Cenozoic of North America and Eurasia: New evidence suggesting early diversification within the Lythraceae

by Fridgeir Grimsson

2011
Fridgeir Grimsson, Reinhard Zetter, Christa-Charlotte Hofmann
American Journal of Botany

Fagus from the Miocene of Iceland: systematics and biogeographical considerations

by Fridgeir Grimsson

2005
Fridgeir Grimsson, Thomas Denk
Review of Palaeobotany and Palynology