Global urban environmental change drives adaptation in white clover.

Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban-rural gradients were associated with the evolution of clines in defense in 47% of cities throughout the world. Variation in the strength of clines was explained by environmental changes in drought stress and vegetation cover that varied among cities. Sequencing 2074 genomes from 26 cities revealed that the evolution of urban-rural clines was best explained by adaptive evolution, but the degree of parallel adaptation varied among cities. Our results demonstrate that urbanization leads to adaptation at a global scale

A bloom of Dinophysis acuta in a thin layer off North-West Portugal

Dinophysis acuta, which is responsible for diarrhetic shellfish poisoning, reached particularly high concentrations on the north-west coast of Portugal in 2003. In the Ría de Aveiro (40°41’N), the species reached a maximumconcentration of 5.0 X 104 cells l–1 on 8 September, the highest value in a 17-year record of monitoring. The bloom followed a brief period of upwelling-favourable winds, at the end of an extremely hot summer marked by weak upwelling, thereby favouring the developmentof highly stratified conditions. In mid-September, during a cruise transecting the shelf 30km south of Aveiro, a subsurface maximum of D. acuta was identified by fluorescence, with cell concentrations exceeding 2.4 X 104 cells l–1. The species was restricted to a relatively thin layer of 5m (with maxima between 18m and 20m depth) within the pycnocline extending 30km offshore. Crossshelf distributions revealed the presence of two smaller forms of D. acuta, the smallest of which was identifiedas D. dens. Their coincident distribution with that of D.acuta reinforced the supposition that these smaller forms correspond to different life-cycle stages of D. acuta, with D. dens representing a gamete of D. acuta.The high cell concentrations in the thin layer are thought to embody a species’ strategy to ensure successful gamete mating during sexual reproduction