Projekt

Zurück zur Übersicht

Gene dynamics in heterogeneous metapopulations

Titel Englisch Gene dynamics in heterogeneous metapopulations
Gesuchsteller/in Vuilleumier Séverine
Nummer 139421
Förderungsinstrument Ambizione
Forschungseinrichtung Département d'Ecologie et d'Evolution Faculté de Biologie et de Médecine Université de Lausanne
Hochschule Universität Lausanne - LA
Hauptdisziplin Oekologie
Beginn/Ende 01.01.2012 - 31.12.2013
Bewilligter Betrag 274'748.00
Alle Daten anzeigen

Alle Disziplinen (2)

Disziplin
Oekologie
Genetik

Lay Summary (Englisch)

Lead
Lay summary

Natural populations can generally have a strong spatial structure and inhabit heterogeneous and dynamic environments which impact their ecology, genetics and evolution. However, theoretical investigations in those fields frequently neglect the importance of heterogeneity and dynamics of the environment and commonly assume a homogeneous environment.

In theoretical studies, models of migration are often used without justification even if they can have drastic consequences on the prediction of the ecology, genetic and evolution of metapopulation. When populations differ in productivity, two main models of migration type that characterizes the rate of individual exchanges between populations can be found in the literature. They are the source-sink and the balanced migration model. For the migration distance, most of theoretical models use either extreme models of isolation by distance: the stepping-stone model and island model or a restricted family of dispersal distance distributions. In order to delineate the conditions under which some metapopulation structures are more likely to emerge, the first section of this follow-up research project aims to model the evolution of migration rate and distance in a heterogeneous metapopulation considering various forms of habitats distributions, heterogeneity and fragmentation.

Environmental heterogeneity by creating gradients such as prevailing winds, ocean and river currents can modify or constrain species migration patterns. Similarly, the structure of the environment can form dendritic networks (river networks, watersheds and cave ecosystems) in which populations can be either strongly locally connected or disconnected. Studies of a variety of empirical systems have shown that island and isolation-by-distance metapopulation models with homogeneous re-colonization patterns cannot capture the dynamics, nor the genetic structure, of such metapopulations. They all directly affect the genetic forces within a metapopulation and thus the genetic diversity and the evolutionary potential of populations. The second part of this research project aims to quantify the impact of asymmetric migration pattern induced by environment heterogeneity on gene flow and the resulting genetic diversity.

During the millions years of species life-time, repeated events of disconnection and reconnection have occurred and have cyclically modified habitats and thus species distribution (isolated refugia during glaciations, the reduction of sea levels allowing migration events, fragmentation and fusion of great lake basins, periodic isolation and fusion of islands). Those short and long-term environmental cycles in which habitat alternately contracts (with fragmentation) and expands (with defragmentation) have shaped the nowadays species diversity and distributions. Nowadays anthropogenic disturbance (e.g. urbanization, agriculture) and climate change also play an important role in modifying the connectivity among populations, when some species suffer from habitat reduction and fragmentation, others experience habitat and population’s expansion. Process described above creates event of connection and disconnection that can occur cyclically. The temporal change in connectivity has been poorly explored even if they are expected to strongly contribute to the nowadays observed macro-evolutionary and macro-ecological patterns of species diversity. Thus how long and short environmental cycles can affect the genetic signature of populations remain an open question. This is the subject of the third and last part of this research proposal.

The proposed research aims to go further in the understanding and quantifying the dynamics of genes across a wide range of situations in heterogeneous landscapes. It will provide the description and the quantification of gene diversity and the fixation in neutral or adaptive environments. Results are expected to make a crucial contribution in the estimation of genetic variance in heterogeneous and dynamic environments.The expected results are directly relevant to conservation (e.g. estimation of metapopulation viability, re-colonization potential, genetic diversity), to the evolution of populations (e.g. adaptation to novel environment, coevolutionary dynamics, evolution of marginal population) and guidelines for the management and conservation of natural populations.

Direktlink auf Lay Summary Letzte Aktualisierung: 21.02.2013

Verantw. Gesuchsteller/in und weitere Gesuchstellende

Mitarbeitende

Publikationen

Publikation
Evolution of uni- and bifactorial sexual compatibility systems in fungi
Nieuwenhuis B., Billiard S., Vuilleumier S., Petit E., Hood M.E., Giraud T. (2013), Evolution of uni- and bifactorial sexual compatibility systems in fungi, in Heredity, 111(6), 445-455.
Peak and Persistent Excess of Genetic Diversity Following an Abrupt Migration Increase.
Alcala Nicolas, Streit Daniela, Goudet Jérôme, Vuilleumier Séverine (2013), Peak and Persistent Excess of Genetic Diversity Following an Abrupt Migration Increase., in Genetics, 193(3), 953-971.
Transitions from reproductive systems governed by two self-incompatible loci to one in fungi.
Vuilleumier Severine, Alcala Nicolas, Niculita-Hirzel Helene (2013), Transitions from reproductive systems governed by two self-incompatible loci to one in fungi., in Evolution, 67(2), 501-516.
Uncovering the genetic basis of adaptive change: on the intersection of landscape genomics and theoretical population genetics
Joost Stéphane, Vuilleumier Séverine, Jensen Jeffrey, Schoville Sean, Leempoel Kevin, Stucki Sylvie, Widmer Ivo, Melodelima Christelle, Rolland Jonathan, Manel Stéphanie (2013), Uncovering the genetic basis of adaptive change: on the intersection of landscape genomics and theoretical population genetics, in Molecular Ecology , 22(14), 3659-3665.
Dispersal Strategies, Few Dominating or Many Coexisting: The Effect of Environmental Spatial Structure and Multiple Sources of Mortality
Buchi L, Vuilleumier S (2012), Dispersal Strategies, Few Dominating or Many Coexisting: The Effect of Environmental Spatial Structure and Multiple Sources of Mortality, in PLOS ONE, 7(4), e34733-e34733.
Interacting populations in heterogeneous environments
Vuilleumier S, Possingham HP (2012), Interacting populations in heterogeneous environments, in ECOLOGICAL MODELLING, 228, 96-105.
Coexistence of specialist and generalist species is shaped by dispersal and environmental factors
Büchi Lucie, Vuilleumier S., Coexistence of specialist and generalist species is shaped by dispersal and environmental factors, in The American Naturalist .

Wissenschaftliche Veranstaltungen

Aktiver Beitrag

Titel Art des Beitrags Titel des Artikels oder Beitrages Datum Ort Beteiligte Personen
Invited seminar (invited by Prof. Jensen) Einzelvortrag 11.10.2013 EPFL, Lausanne, Schweiz Vuilleumier Séverine;
Mathematics of Planet Earth 2013, Workshop on Mathematics for an Evolving Biodiversity Vortrag im Rahmen einer Tagung 16.09.2013 Ottawa, Kanada Vuilleumier Séverine;
ESEB 2013 Poster 19.08.2013 Lisbon, Portugal Vuilleumier Séverine;
Evolution Vortrag im Rahmen einer Tagung 21.06.2013 Snowbird (Utah), Vereinigte Staaten von Amerika Vuilleumier Séverine;
On the intersection of landscape genomics and theoretical population genetics Vortrag im Rahmen einer Tagung 13.12.2012 Lausanne, Schweiz Vuilleumier Séverine;
Seminar series Einzelvortrag 07.11.2012 Angers, Frankreich Vuilleumier Séverine;
Monod Conference: Recent advances on the evolution of sex and genetic systems Vortrag im Rahmen einer Tagung 04.09.2012 Roscoff, Frankreich Vuilleumier Séverine;
Seminar series Einzelvortrag 04.09.2012 Vienne, Österreich Vuilleumier Séverine;
Evolution, 1st Joint Congress on Evolutionary Biology Vortrag im Rahmen einer Tagung 06.07.2012 Ottawa, Kanada Vuilleumier Séverine;
Evolution of sex-determination mechanisms Vortrag im Rahmen einer Tagung 06.06.2012 La Sage, Suisse, Schweiz Vuilleumier Séverine;


Verbundene Projekte

Nummer Titel Start Förderungsinstrument
121702 Dynamique des gènes en métapopulations hétérogènes 01.01.2009 Ambizione
158381 Recent Evolutionary History of HIV: worldwide pattern of introgression and the genetic compartmentalization hypothesis 01.09.2015 Marie Heim-Voegtlin Beiträge
130065 Evolution of metapopulation structure under local adaptation 01.09.2010 Projektförderung (Abt. I-III)

Abstract

Natural populations can generally have a strong spatial structure and inhabit heterogeneous and dynamic environments which impact their ecology, genetics and evolution. However, theoretical investigations in those fields frequently neglect the importance of heterogeneity and dynamics of the environment and commonly assume a homogeneous environment. In theoretical studies, models of migration are often used without justification even if they can have drastic consequences on the prediction of the ecology, genetic and evolution of metapopulation. When populations differ in productivity, two main models of migration type that characterizes the rate of individual exchanges between populations can be found in the literature. They are the source-sink and the balanced migration model. For the migration distance, most of theoretical models use either extreme models of isolation by distance: the stepping-stone model and island model or a restricted family of dispersal distance distributions. In order to delineate the conditions under which some metapopulation structures are more likely to emerge, the first section of this follow-up research project aims to model the evolution of migration rate and distance in a heterogeneous metapopulation considering various forms of habitats distributions, heterogeneity and fragmentation. Environmental heterogeneity by creating gradients such as prevailing winds, ocean and river currents can modify or constrain species migration patterns. Similarly, the structure of the environment can form dendritic networks (river networks, watersheds and cave ecosystems) in which populations can be either strongly locally connected or disconnected. Studies of a variety of empirical systems have shown that island and isolation-by-distance metapopulation models with homogeneous re-colonization patterns cannot capture the dynamics, nor the genetic structure, of such metapopulations. They all directly affect the genetic forces within a metapopulation and thus the genetic diversity and the evolutionary potential of populations. The second part of this research project aims to quantify the impact of asymmetric migration pattern induced by environment heterogeneity on gene flow and the resulting genetic diversity.During the millions years of species life-time, repeated events of disconnection and reconnection have occurred and have cyclically modified habitats and thus species distribution (isolated refugia during glaciations, the reduction of sea levels allowing migration events, fragmentation and fusion of great lake basins, periodic isolation and fusion of islands). Those short and long-term environmental cycles in which habitat alternately contracts (with fragmentation) and expands (with defragmentation) have shaped the nowadays species diversity and distributions. Nowadays anthropogenic disturbance (e.g. urbanization, agriculture) and climate change also play an important role in modifying the connectivity among populations, when some species suffer from habitat reduction and fragmentation, others experience habitat and population’s expansion. Process described above creates event of connection and disconnection that can occur cyclically. The temporal change in connectivity has been poorly explored even if they are expected to strongly contribute to the nowadays observed macro-evolutionary and macro-ecological patterns of species diversity. Thus how long and short environmental cycles can affect the genetic signature of populations remain an open question. This is the subject of the third and last part of this research proposal. The proposed research aims to go further in the understanding and quantifying the dynamics of genes across a wide range of situations in heterogeneous landscapes. It will provide the description and the quantification of gene diversity and the fixation in neutral or adaptive environments. Results are expected to make a crucial contribution in the estimation of genetic variance in heterogeneous and dynamic environments.The expected results are directly relevant to conservation (e.g. estimation of metapopulation viability, re-colonization potential, genetic diversity), to the evolution of populations (e.g. adaptation to novel environment, coevolutionary dynamics, evolution of marginal population) and guidelines for the management and conservation of natural populations.
-