| 1. |
- Björklund, Mats, et al.
(författare)
-
Quantitative Trait Evolution and Environmental Change
- 2009
-
Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 4:2, s. e4521-
-
Tidskriftsartikel (refereegranskat)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. Methodology/Principal Findings: 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.
|
|
| 2. |
- Ranta, Esa, et al.
(författare)
-
Environmental forcing and genetic differentiation in subdivided populations
- 2008
-
Ingår i: Evolutionary Ecology Research. - 1522-0613 .- 1937-3791. ; 10:1, s. 1-9
-
Tidskriftsartikel (refereegranskat)abstract
- Questions: How will genetic differentiation and genetic drift in spatially structured populations be affected by different classes of autocorrelated environmental noise? How does dispersal interact with fluctuations generated from the demographic and environmental forcing in shaping the neutral genetic patterns? Model and key assumptions: Populations are regulated locally by density-dependent feedback including demographic stochasticity but they are also here forced by environmental noise (white, red, and blue noise corresponding to random, positive, and negative autocorrelation respectively). Spatial structure consists of a looped string of populations connected by dispersal and each with a predefined carrying capacity (one-dimensional stepping stone structure). Method: Simulations initialized by randomly distributing individuals, and thus genotypes, in space (no fitness differences, no mutation, no recombination, no selection). Conclusions: In an unpredictable way, red noise reinforces the genetic differentiation among populations more than white or blue noise. Dispersal appears unable to dilute the differentiation effect of positively autocorrelated forcing. In modelling the effect of environmental stochasticity, details about the type of environmental noise are of paramount importance for the results and their biological and management implications.
|
|
| 3. |
- Stenseth, Nils Chr, et al.
(författare)
-
Gregor Johann Mendel and the development of modern evolutionary biology
- 2022
-
Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences (PNAS). - 0027-8424 .- 1091-6490. ; 119:30
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
|
|
| 4. |
- Yang, Bao, et al.
(författare)
-
Long-term decrease in Asian monsoon rainfall and abrupt climate change events over the past 6,700 years
- 2021
-
Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - Washington : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 118:30
-
Tidskriftsartikel (refereegranskat)abstract
- Asian summer monsoon (ASM) variability and its long-term ecological and societal impacts extending back to Neolithic times are poorly understood due to a lack of high-resolution climate proxy data. Here, we present a precisely dated and well-calibrated treering stable isotope chronology from the Tibetan Plateau with 1- to 5-y resolution that reflects high- to low-frequency ASM variability from 4680 BCE to 2011 CE. Superimposed on a persistent drying trend since the mid-Holocene, a rapid decrease in moisture availability between similar to 2000 and similar to 1500 BCE caused a dry hydroclimatic regime from similar to 1675 to similar to 1185 BCE, with mean precipitation estimated at 42 +/- 4% and 5 +/- 2% lower than during themid-Holocene and the instrumental period, respectively. This second-millennium-BCE megadrought marks the mid-to late Holocene transition, during which regional forests declined and enhanced aeolian activity affected northern Chinese ecosystems. We argue that this abrupt aridification starting similar to 2000 BCE contributed to the shift of Neolithic cultures in northern China and likely triggered human migration and societal transformation.
|
|
