Reconstructing the assembly of island biotas on evolutionary time scales: a phylogenetic and modelling approach

• Applicant: Dr. Thomas von Rintelen, since 6/2019
• Subject Area: Evolution, Anthropology
• Term: from 2016 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 310335869

Understanding how species diversity varies through time is one of the key questions in biology. Reconstructing how global biodiversity changes on continents over evolutionary time scales (thousands to millions of years) is a difficult challenge, owing to the high number of species and to many confounding factors that erase signatures of the relevant processes. Due to their isolation, defined boundaries and comparatively lower species richness, islands constitute the ideal model systems for investigating biological processes that often prove too complex to study on continents. Despite recent advances in understanding how diversity accumulates on islands, several questions remain unanswered.Biodiversity emerges from the interplay between colonisation, speciation and extinction, but we still know surprisingly little regarding how these processes vary globally with island features such as age, area and isolation. We also still do not know whether species diversity is unbounded (can grow without limits) or whether it is regulated by equilibrium processes (tends towards a constant number of species). In addition, recent developments have mostly focused on oceanic islands (that have never been connected to other landmasses) but the majority of islands have at least once been connected to continents (non-oceanic islands), and thus research has often neglected an important proportion of island systems. The present proposal will address these issues by developing novel dynamic models of island biogeography and applying them to newly-generated molecular phylogenies from both oceanic and non-oceanic islands. The aim of the project is to reconstruct the pattern of species accumulation on multiple islands worldwide in order to understand how island features, species interactions and historical events (e.g. formation of new islands and fusion of landmasses) shape species richness in isolated environments on a global scale. This innovative proposal will produce the first global dataset on the times of bird species colonisation on islands and will be the first to investigate the existence of an island-wide diversity limit (maximum number of species each island can contain). The project will produce pioneering phylogenetic models that will deal explicitly with non-oceanic islands (which will be tested using data from Socotra and Sulawesi islands), and will thus stimulate future research on these understudied systems. All methods developed will be implemented in a new software package that will be created with the aim of becoming the standard tool for studies of island biogeography using phylogenetic data. This project will provide a novel baseline framework for the study of long-term evolutionary dynamics in isolated environments and will deliver much anticipated answers to a topic with wide implications for biodiversity and conservation on continents.

• DFG Programme: Research Grants
• International Connection: Netherlands, United Kingdom
• Cooperation Partners: Professor Rampal Etienne, Ph.D.; Dr. Albert Phillimore
• Ehemaliger Antragsteller: Luis Valente, Ph.D., until 5/2019