Objective Many emerging infectious diseases and novel agricultural pests are attributed to the adaptation and spread of parasitic organisms to new hosts, but almost nothing is known about the characteristics of parasites with this potential and the implications of this shift for interacting organisms. In vector organisms, those that exploit a host to which they will transmit a microparasite, the evolution of host-associated divergence may be of particular importance, especially for the evolution of the microparasites they carry. However, little work has been done on parasite adaptation involving multispecific interactions. Ticks are second only to mosquitoes in their global importance as disease vectors and they transmit numerous pathogens of medical and veterinary interest. These “vertebrate host-tick-micropathogen” systems therefore represent pertinent models to examine the evolution and implications of vector adaptation. In this scientific context, we aim to answer; 1) How readily ticks adapt to their host environments? 2) How does divergence in the vector affect the distribution of micropathogens? 3) What is the relative importance of the arthropod vector versus the vertebrate host in the evolution and epidemiology of vector-borne diseases? These questions will be addressed using two complimentary systems: the seabird ticks Ixodes uriae vector of Borrelia burgdorferi s.l. the pathogen responsible for human Lyme disease and Ornithodoros maritimus, and potential vector of relapsing fever Borrelia. Although the epidemiologies of both Lyme disease and relapsing fever have been widely studied in terrestrial ecosystems, the prevalence and spatial distribution of the associated bacteria in the marine ecosystem have been largely neglected. This project will shed light on the nature of host-associated adaptation in vectors and the influence of spatial structure on this process and will help determine the relative importance of vectors in the evolution of their micropathogens. Fields of science medical and health scienceshealth sciencespublic healthepidemiologymedical and health scienceshealth sciencesparasitologymedical and health scienceshealth sciencesinfectious diseases Keywords Argasidae Ectoparasites Emerging diseases Epidemiology Evolutionary biology Ixodidae Marine birds Molecular biology Parasitology Pathogens Phylogeography Population genetics Zoonoses Programme(s) FP7-PEOPLE - Specific programme "People" implementing the Seventh Framework Programme of the European Community for research, technological development and demonstration activities (2007 to 2013) Topic(s) PEOPLE-2007-2-1.IEF - Marie Curie Action: "Intra-European Fellowships for Career Development" Call for proposal FP7-PEOPLE-2007-2-1-IEF See other projects for this call Funding Scheme MC-IEF - Intra-European Fellowships (IEF) Coordinator CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS Address Rue michel ange 3 75794 Paris France See on map Region Ile-de-France Ile-de-France Paris Administrative Contact Jocelyn Mere (Mr.) Links Contact the organisation Opens in new window Website Opens in new window EU contribution € 161 942,68