Transposuns

EurekAlert summarizes work by Mark Ungerer and his colleagues at Kansas State University which is set to appear in the 24 October issue of Current Biology. They

determined that the genome size differences between … hybrid and parental sunflower species are associated with a massive proliferation of transposable genetic elements that has occurred independently in the genome of each hybrid species.

This is interesting because each of the three hybrid species studied has evolved under strong abiotic stress (in deserts, salt marshes). It has been suggested that both hybridization and abiotic stress can activate and lead to the multiplication of transposable elements, making this a potentially very valuable model system.

Frozen olives

A paper in the Journal of Biogeography reports on the biggest ever microsatellite study of wild and cultivated olives in the Mediterranean. There is a cline in diversity from east to west, suggesting that perhaps the wild olive in the west is feral rather than truly wild, but this study suggests that the wild olive spread out of 7 RPOPs, or reconstructed panmictic oleaster populations, in both eastern and western Mediterranean, possibly located in glacial refugia. Cultivated olives were domesticated in several RPOPs, and mediated geneflow in the wild species as they were spread around my humans. Has this business of glacial refugia been looked at for other cultivated trees in Europe?