Demogenetics in metapopulations

Détails

Demande d'une copie
ID Serval
serval:BIB_F67F724C0A5B
Type
Thèse: thèse de doctorat.
Collection
Publications
Titre
Demogenetics in metapopulations
Auteur(s)
Jaquiéry J.
Directeur(s)
Perrin N.
Institution
Université de Lausanne, Faculté de biologie et médecine
Adresse
Faculté de biologie et de médecine Université de Lausanne UNIL - Bugnon Rue du Bugnon 21 - bureau 4111 CH-1015 Lausanne SUISSE
Statut éditorial
Acceptée
Date de publication
2008
Langue
anglais
Nombre de pages
201
Notes
REROID:R004763260 ill.
Résumé
SUMMARY :
Human-induced habitat fragmentation constitutes a major threat to biodiversity. Small and isolated populations suffer from increased stochasticity and from limited rescue effects. These two factors may be sufficient to cause local extinctions but fragmentation induces some genetic consequences that can also contribute significantly to extinction risks. Increased genetic drift reduces the effectiveness of selection against deleterious mutations, leading to their progressive accumulation. Drift also decreases both the standing genetic variation and the rate of fixation of beneficial mutations, limiting the evolutionary potential of isolated populations. Demography and genetics further interact and feed back on each other, progressively driving fragmented populations into "extinction vortices".
The aim of the thesis was to better understand the processes occurring in fragmented populations. For this, I combined simulation studies and empirical data from three species that live in structured habitats. Chapter 1 and 2 investigate the demography of two shrew species in fragmented habitats. I showed that connectivity and habitat quality strongly affect the demography of the greater white-tooted shrew, although demographic stochasticity was extremely high. I also demonstrated that habitat fragmentation is one of the leading factors allowing the local coexistence of two competing shrew species. Chapter 3 and 4 focus on measuring connectivity in fragmented populations based on genetic data. In particular, I showed that genetic data can be used to detect the landscape elements impeding dispersal. In Chapter 5 that deals with the accumulation of deleterious mutations in fragmented populations, I demonstrated that mutation accumulation, as well a time to extinction, can be predicted from simple demographic and genetic measures. In the last two chapters, I monitored individual reproductive success in an isolated tree frogs population. These data allowed quantifying the effective population size, a measure closely linked to population evolutionary potential.
To conclude, this thesis brings some new insights into the processes occurring in fragmented populations, and I hope it will contribute to the improvement of the management and conservation of fragmented populations.
Création de la notice
22/06/2010 15:28
Dernière modification de la notice
03/03/2018 22:48
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