Biogeography and pace of diversification in the Guiana Shield (PHYLOGUIANAS)

Programme : Labex CEBA
Durée : 2013 - 2016

Mots clés

Biodiversité, Biogéographie, Bouclier Guyanais

Résumé

The historical causes and regional determinants of the outstanding Amazonian diversity remain speculative, and the ability of tropical biomes to withstand major environmental changes, poorly known. Predicting how biodiversity will respond to these environmental changes is a major challenge facing ecologists, and a macroevolutionary perspective help understand how environmental changes have affected biodiversity in the past. Here we propose to build on phylogenomics techniques and regional paleoclimatic modeling to bridge a gap in the knowledge of the macroevolutionary patterns for selected lineages in the Guiana Shield. This project will primarily focus on the Guiana Shield, a Precambrian craton within the South American plate which has remained emerged and located around the tropics for the past 200 Myr. We will assemble and compile data for three groups of organisms: harvestmen (Opiliones) in the arthropods, anurans (specifically genus Anomaloglossus), and flowering plants (specifically the tribe Sipaneeae in the Rubiaceae, the Chrysobalanaceae and the Caryocaraceae). Fully resolved phylogenetic trees will be constructed using state of the art techniques in phylogenomics. The past 100 Ma of climatic changes in South America will be modelled using regional models and reconstructed topography. Finally, this unique information will be used to address the three following questions: (1) what proportion of the Guiana Shield lineages are likely to have arisen in situ, versus those that may have arisen elsewhere in the Neotropics and subsequently dispersed toward the Guiana Shield? (2) How old are the Guianan lineages and are they older or younger than other Neotropical lineages (and what role may the Tertiary/Quaternary climate history have played in the diversification of Amazonian lineages)? (3) Which proportion of species and lineages show major break points in their distributions (putative areas of vicariance) in this region? Through the quality of the field sampling, a network of experienced collaborating taxonomists and novel techniques, we hope to bring a renewed perspective to the patterns of diversification in the Guiana Shield.

Collaborations

  • UMR EDB (Toulouse)
  • UMR BIOGECO (Bordeaux)
  • UMR LEEISA (Cayenne)
  • UMR EcoFoG (Kourou)
  • LECA (Grenoble)
  • LSCE (Gif-sur-Yvette)