title: Quantitative trait evolution and environmental change.
abstract: BACKGROUND
  Given the recent changes in climate, there is an urgent need to understand the evolutionary ability of populations to respond to these changes.
  
  
  RESULTS
  We performed individual-based simulations with different shapes of the fitness curve, different heritabilities, different levels of density compensation, and different autocorrelation of environmental noise imposed on an environmental trend to study the ability of a population to adapt to changing conditions. The main finding is that when there is a positive autocorrelation of environmental noise, the outcome of the evolutionary process is much more unpredictable compared to when the noise has no autocorrelation. In addition, we found that strong selection resulted in a higher load, and more extinctions, and that this was most pronounced when heritability was low. The level of density-compensation was important in determining the variance in load when there was strong selection, and when genetic variance was lower when the level of density-compensation was low.
  
  
  CONCLUSIONS
  The strong effect of the details of the environmental fluctuations makes predictions concerning the evolutionary future of populations very hard to make. In addition, to be able to make good predictions we need information on heritability, fitness functions and levels of density compensation. The results strongly suggest that patterns of environmental noise must be incorporated in future models of environmental change, such as global warming.
authors.affiliation: Department of Animal Ecology, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden. Mats.Bjorklund@ebc.uu.se
authors.forename: Mats
authors.initials: M
authors.lastname: Björklund
authors.forename: Esa
authors.initials: E
authors.lastname: Ranta
authors.forename: Veijo
authors.initials: V
authors.lastname: Kaitala
authors.forename: Lars A
authors.initials: LA
authors.lastname: Bach
authors.forename: Per
authors.initials: P
authors.lastname: Lundberg
authors.forename: Nils Chr
authors.initials: NC
authors.lastname: Stenseth
mesh_terms: D005075:Biological Evolution; D003198:Computer Simulation; D004777:Environment; D005544:Forecasting; D005828:Genetics, Population; D017752:Greenhouse Effect; D006801:Humans; D008962:Models, Theoretical; D019655:Quantitative Trait, Heritable