Cryptic diversity among Western Palearctic tree frogs: postglacial range expansion, range limits, and secondary contacts of three European tree frog lineages (Hyla arborea group).

We characterize divergence times, intraspecific diversity and distributions for recently recognized lineages within the Hyla arborea species group, based on mitochondrial and nuclear sequences from 160 localities spanning its whole distribution. Lineages of H. arborea, H. orientalis, H. molleri have at least Pliocene age, supporting species level divergence. The genetically uniform Iberian H. molleri, although largely isolated by the Pyrenees, is parapatric to H. arborea, with evidence for successful hybridization in a small Aquitanian corridor (southwestern France), where the distribution also overlaps with H. meridionalis. The genetically uniform H. arborea, spread from Crete to Brittany, exhibits molecular signatures of a postglacial range expansion. It meets different mtDNA clades of H. orientalis in NE-Greece, along the Carpathians, and in Poland along the Vistula River (there including hybridization). The East-European H. orientalis is strongly structured genetically. Five geographic mitochondrial clades are recognized, with a molecular signature of postglacial range expansions for the clade that reached the most northern latitudes. Hybridization with H. savignyi is suggested in southwestern Turkey. Thus, cryptic diversity in these Pliocene Hyla lineages covers three extremes: a genetically poor, quasi-Iberian endemic (H. molleri), a more uniform species distributed from the Balkans to Western Europe (H. arborea), and a well-structured Asia Minor-Eastern European species (H. orientalis).

Timeframe of speciation inferred from secondary contact zones in the European tree frog radiation (Hyla arborea group).

BACKGROUND: Hybridization between incipient species is expected to become progressively limited as their genetic divergence increases and reproductive isolation proceeds. Amphibian radiations and their secondary contact zones are useful models to infer the timeframes of speciation, but empirical data from natural systems remains extremely scarce. Here we follow this approach in the European radiation of tree frogs (Hyla arborea group). We investigated a natural hybrid zone between two lineages (Hyla arborea and Hyla orientalis) of Mio-Pliocene divergence (~5 My) for comparison with other hybrid systems from this group. RESULTS: We found concordant geographic distributions of nuclear and mitochondrial gene pools, and replicated narrow transitions (~30 km) across two independent transects, indicating an advanced state of reproductive isolation and potential local barriers to dispersal. This result parallels the situation between H. arborea and H. intermedia, which share the same amount of divergence with H. orientalis. In contrast, younger lineages show much stronger admixture at secondary contacts. CONCLUSIONS: Our findings corroborate the negative relationship between hybridizability and divergence time in European tree frogs, where 5 My are necessary to achieve almost complete reproductive isolation. Speciation seems to progress homogeneously in this radiation, and might thus be driven by gradual genome-wide changes rather than single speciation genes. However, the timescale differs greatly from that of other well-studied amphibians. General assumptions on the time necessary for speciation based on evidence from unrelated taxa may thus be unreliable. In contrast, comparative hybrid zone analyses within single radiations such as our case study are useful to appreciate the advance of speciation in space and time.

Cooperation versus competition effects on information sharing and use in group decision making

Information processing in groups has long been seen as a cooperative process. In contrast with this assumption, group members were rarely found to behave cooperatively: They withhold unshared information and stick to initial incorrect decisions. In the present article, we examined how group members' cooperative and competitivemotives impact on group information processing and propose that information sharing and use in groups could be seen as strategic behavior. We reviewed the latest developments in the literature investigating different forms of strategic information processing and their underlying mechanisms. This review suggests that explicit cooperative goals are needed for effective group decision-making.

Diversity and geographical distribution of phytoplasmas infecting China-tree in Argentina

Yellows diseases associated with phytoplasmas cause high mortality in China-tree (Melia azedarach) in Argentina, but there has been no previous large-scale survey to determine their diversity and geographical distribution. To assess the presence and identity of phytoplasmas affecting this species throughout the country, 425 samples of symptomatic trees collected at different geographic locations were analysed by a polymerase chain reaction (using universal and group-specific primers) and restriction fragment length polymorphism. Phytoplasmas belonging to 16SrIII-B group were detected at almost every location sampled, whereas 16SrXIII-C group phytoplasmas, reported for the first time in Argentina, were only found in two regions sharing similar agro-ecological characteristics (Northeast provinces and Tucuman). Double infections with 16SrIII-B and 16SrXIII-C group phytoplasmas were also recorded. Nucleotide sequencing of the 16S rDNA of three Argentinian 16SrXIII-C group phytoplasma isolates revealed high identity (99.6-99.3%) with the CbY1 isolate reported from Bolivia.

Informe del Grupo de Trabajo Intersecretarial sobre Recursos Hídricos en América Latina = Report of the Inter-Secretariat Working Group on Water Resources in Latin America

Incluye Bibliografía

Informe del Grupo de Trabajo Intersecretarial sobre Recursos Hídricos en América Latina = Report of the Inter-Secretariat Working Group on Water Resources in Latin America

Informe de la reunion sobre recursos hidricos cuyos puntos principales fueron: el examen y coordinacion de las actividades desarrolladas en el terreno y de las realizadas de acuerdo al programa ordinario en la esfera de los recursos hidricos, y arreglos para examinar la marcha de la aplicacion del Plan de Accion de Mar del Plata. Incluye temario, resumen de los debates, lista de participantes y de documentos.

Report of the Joint Meeting of the SIDS Bureau and the Inter-Agency Collaborative Group

Summary An account of the proceedings of the meeting which discussed the following agenda items: report on regional implementation of the SIDS POA; status of regional projects for submission to the meeting of prospective donors and representatives of Small Island Developing States; the regional position on UNDP compendium of project proposals; status of consultations with CARIFORUM and the EU; budget for the regional co-ordinating mechanism and consultation; preparation for the Special Session on the UN General Assembly (UNGASS); to discuss the SIDS plan of action; and a Ministerial meeting on SIDS POA implementation.

Report of the ECLAC Expert Group meeting on data sharing, data ownership and harmonization of survey datasets

Includes bibliography

Report of the Inter-Agency Collaborative Group Meeting Preparatory to the Review and Appraisal of the Implementation of the World Summit for Social Development

El informe da cuenta de las discusiones sostenidas en la reunión, las que se centraron en: a) la revisión y evaluación de la implementación del Programa de Acción de la Cumbre Mundial para el Desarrollo Social, con énfasis en las actividades específicas incluyendo informes por países y estudios temáticos en torno al empleo, la erradicación de la pobreza y la integración social; b) el examen de la situación del envejecimiento y de los ancianos, relevando las necesidades de información para la implementación de políticas, las estrategias y programas, y el logro de un consenso subregional frente a la tercera edad.