Timing and Tempo of Early and Successive Adaptive Radiations in Macaronesia

The flora of Macaronesia, which encompasses five Atlantic archipelagos (Azores, Canaries, Madeira, Cape Verde, and Salvage), is exceptionally rich and diverse

Surviving in isolation: genetic variation, bottlenecks and reproductive strategies in the Canarian endemic Limonium macrophyllum (Plumbaginaceae)

Oceanic archipelagos are typically rich in endemic taxa, because they offer ideal conditions for diversification and speciation in isolation. One of the most remarkable evolutionary radiations on the Canary Islands comprises the 16 species included in Limonium subsection Nobiles, all of which are subject to diverse threats, and legally protected. Since many of them are single-island endemics limited to one or a few populations, there exists a risk that a loss of genetic variation might limit their longterm survival. In this study, we used eight newly developed microsatellite markers to characterize the levels of genetic variation and inbreeding in L. macrophyllum, a species endemic to the North-east of Tenerife that belongs to Limonium subsection Nobiles. We detected generally low levels of genetic variation over all populations (HT = 0.363), and substantial differentiation among populations (FST = 0.188;RST = 0.186) coupled with a negligible degree of inbreeding (F = 0.042). Obligate outcrossing may have maintained L. macrophyllum relatively unaffected by inbreeding despite the species’ limited dispersal ability and the genetic bottlenecks likely caused by a prolonged history of grazing. Although several factors still constitute a risk for the conservation of L. macrophyllum, the lack of inbreeding and the recent positive demographic trends observed in the populations of this species are factors that favour its future persistence

Los datos moleculares confirman las afinidades de los granitos endémicos del suroeste de Australia con Alphitonia (Rhamnaceae)

Sobre la base de los datos de la secuencia de ADN, se confirma que las afinidades del género Granitites (Rhamnaceae) recientemente descrito del sudoeste de Australia están con Alphitonia, como sugirió Rye (1996), en lugar de miembros de Pomaderreae, como pensaron autores anteriores. . Los hallazgos de este estudio proporcionan una confirmación molecular de que algunos componentes de la flora del suroeste de Australia pueden ser reliquias de antiguos linajes de la selva tropicalOn the basis of DNA sequence data, the affinities of the recently described genus Granitites (Rhamnaceae) from south-western Australia are confirmed to be with Alphitonia, as suggested by Rye (1996), rather than members of Pomaderreae, as thought by earlier authors. The findings of this study provide molecular confirmation that some components of the south-west Australian flora may be relicts of old rainforest lineages