Séminaires de George RODERICK et Rosemary GILLESPIE (University of Berkley)



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Le lundi 20 novembre 2017 à 12h00, salle de conférences de l'OSUR, bâtiment 14b, Campus de Beaulieu, UR1

Le lundi 20 novembre 2017 à 12h00, salle de conférences de l'OSUR, bâtiment 14b, Campus de Beaulieu, UR1

Invasive species, novel management, and sustainability, on Moorea, French Polynesia

With increased globalization, invasive species continue to have a large impact on natural and managed ecosystems worldwide. Because of their confined boundaries and unique biota islands are particularly well suited for studies of both the impacts of invasive, species but also their management and how society adapts to their presence. Here, I first report on an all taxon DNA survey of Moorea, the Moorea BioCode Project (https://mooreabiocode.org) including both terrestrial and marine habitats. I focus on terrestrial insects to demonstrate how DNA-barcode data can be used to classify non-native species, allowing us to assess more accurately the impacts of invasive species in both natural and managed habitats. Islands offer opportunities for ecosystem-level manipulations targeted at control. One example, in collaboration with the Délégation à la Recherche de la Polynésie française, is the biological control of the glassy-winged sharpshooter achieved by importation of parasitoid predators, which also revealed a biosecurity threat associated with movements of people and goods in the Pacific. A second example by Institut Louis Malardé researchers is the removal of mosquito species from small islands, motus, on nearby Tetiaroa using genetically differing strains of the bacterium Wolbachia. Finally, Island systems are also particularly attractive for sustainability science because ongoing studies at larger scales (e.g., global climate models) can help incorporate external influences simply and effectively. I describe the Island Digital Ecosystem Avatars (IDEA) Project (https://mooreaidea.ethz.ch/project) with the goal to model and predict a sustainable future with islands as a model.

Contact : George RODERICK

 

Origins of diversity in islands: the nexus of ecology and evolution in community assembly

Research on the dynamics of biodiversity has progressed tremendously over recent years, though in two separate directions – ecological, to determine change over space at a given time, and evolutionary, to understand change over time. Integration of these approaches has remained elusive. Archipelagoes with a known geological chronology provide an opportunity to study ecological interactions over evolutionary time. In this presentation I will focus on the Hawaiian archipelago and summarize the development of ecological, and evolutionary research; I emphasize spiders because they have attributes allowing analysis of ecological affinities in concert with diversification. Within this framework, I highlight recent insights from the island chronosequence, in particular (1) the extent to which species diversification is predictable – and why some lineages might show predictable patterns of diversification while others do not. And (2) how the differences between lineages in their patterns of adaptive differentiation appear to be reflected in the patterns of accumulation (under representation or overshoot relative to an island’s carrying capacity). Insights into biodiversity dynamics at the nexus of ecology and evolution are now achievable by integrating new tools. In particular, large-scale metabarcoding efforts provide data on species abundance, diversity, and interactions. Coupling this with ecological metrics (interaction networks, species abundance distributions) across the chronosequence can uncover the evolutionary dynamics of the entire community, showing not only how diversity has been shaped in the past, but also how it will be expected to accommodate change in the future.

Contact: Rosemary GILLESPIE





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