The Experts below are selected from a list of 12531 Experts worldwide ranked by ideXlab platform

Li Yang - One of the best experts on this subject based on the ideXlab platform.

Irja Ida Ratikainen - One of the best experts on this subject based on the ideXlab platform.

  • individual reversible plasticity as a genotype level bet Hedging Strategy
    Journal of Evolutionary Biology, 2021
    Co-Authors: Thomas Ray Haaland, Jonathan Wright, Irja Ida Ratikainen
    Abstract:

    Reversible plasticity in phenotypic traits allows organisms to cope with environmental variation within lifetimes, but costs of plasticity may limit just how well the phenotype matches the environmental optimum. An additional adaptive advantage of plasticity might be to reduce fitness variance, in other words: bet-Hedging to maximize geometric (rather than simply arithmetic) mean fitness. Here, we model the evolution of plasticity in the form of reaction norm slopes, with increasing costs as the slope or degree of plasticity increases. We find that greater investment in plasticity (i.e. a steeper reaction norm slope) is favoured in scenarios promoting bet-Hedging as a response to multiplicative fitness accumulation (i.e. coarser environmental grains and fewer time steps prior to reproduction), because plasticity lowers fitness variance across environmental conditions. In contrast, in scenarios with finer environmental grain and many time steps prior to reproduction, bet-Hedging plays less of a role and individual-level optimization favours evolution of shallower reaction norm slopes. However, the opposite pattern holds if plasticity costs themselves result in increased fitness variation, as might be the case for production costs of plasticity that depend on how much change is made to the phenotype each time step. We discuss these contrasting predictions from this partitioning of adaptive plasticity into short-term individual benefits versus long-term genotypic (bet-Hedging) benefits, and how this approach enhances our understanding of the evolution of optimum levels of plasticity in examples from thermal physiology to advances in avian lay dates.

  • Individual reversible plasticity as a genotype-level bet-Hedging Strategy
    2020
    Co-Authors: Thomas Ray Haaland, Jonathan Wright, Irja Ida Ratikainen
    Abstract:

    Reversible plasticity in phenotypic traits allows organisms to cope with environmental variation within lifetimes, but costs of plasticity may limit just how well the phenotype matches the environmental optimum. An additional adaptive advantage of plasticity might be to reduce fitness variance, or bet-Hedging to maximize geometric (rather than simply arithmetic) mean fitness. Here we model the evolution of reaction norm slopes, with increasing costs as the slope or degree of plasticity increases. We find that greater investment in plasticity (i.e. steeper reaction norm slopes) is favoured in scenarios promoting bet-Hedging as a response to multiplicative fitness accumulation (i.e. coarser environmental grains and fewer time steps prior to reproduction), because plasticity lowers fitness variance across environmental conditions. In contrast, in scenarios with finer environmental grain and many time steps prior to reproduction, bet-Hedging plays less of a role and individual-level optimization favours evolution of shallower reaction norm slopes. We discuss contrasting predictions from this partitioning of the different adaptive causes of plasticity into short-term individual benefits versus long-term genotypic (bet-Hedging) benefits under different costs of plasticity scenarios, thereby enhancing our understanding of the evolution of optimum levels of plasticity in examples from thermal physiology to advances in avian lay dates.

Yudong Wang - One of the best experts on this subject based on the ideXlab platform.

Hong Zou - One of the best experts on this subject based on the ideXlab platform.

  • the effectiveness of using a basis Hedging Strategy to mitigate the financial consequences of weather related risks
    The North American Actuarial Journal, 2010
    Co-Authors: Linda L Golden, Charles C Yang, Hong Zou
    Abstract:

    Abstract This paper examines the effectiveness of using a Hedging Strategy involving a basis derivative instrument to reduce the negative financial consequences of weather-related risks. We examine the effectiveness of using this basis derivative Strategy for both summer and winter seasons, using both linear and nonlinear Hedging instruments and the impacts of default risk and perception errors on weather Hedging efficiency. We also compare the Hedging effectiveness obtained using weather indices produced by both the Chicago Mercantile Exchange (CME) and Risk Management Solutions, Inc. (RMS). The results indicate that basis Hedging is significantly more effective for the winter season than for the summer season, whether using the CME or RMS weather indices, and whether using linear or nonlinear derivative instruments. It is also found that the RMS regional weather indices are more effective than the CME weather indices, and the effectiveness of using either linear or nonlinear Hedging instruments for weat...

  • the effectiveness of using a basis Hedging Strategy to mitigate the financial consequences of weather related risks
    Social Science Research Network, 2009
    Co-Authors: Linda L Golden, Charles C Yang, Hong Zou
    Abstract:

    This paper examines the effectiveness of using a Hedging Strategy involving a basis derivative instrument to reduce the negative financial consequences of weather-related risks. We examine the effectiveness of using this basis derivative Strategy for both summer and winter seasons, using both linear and nonlinear Hedging instruments and the impacts of default risk and perception errors on weather Hedging efficiency. We also compare the Hedging effectiveness obtained using weather indices produced by both the Chicago Mercantile Exchange (CME) and Risk Management Solutions, Inc. (RMS). The results indicate that basis Hedging is significantly more effective for the winter season than for the summer season, whether using the CME or RMS weather indices, and whether using linear or nonlinear derivative instruments. It is also found that the RMS regional weather indices are more effective than the CME weather indices, and the effectiveness of using either linear or nonlinear Hedging instruments for weather risk management can vary significantly depending on the region of the country. In addition, the results indicate that default risk has some impact on nonlinear basis Hedging efficiency but no impact on linear basis Hedging efficiency, and reasonable perception errors on default risk have no impact on either linear or nonlinear basis Hedging efficiency.

Thomas Ray Haaland - One of the best experts on this subject based on the ideXlab platform.

  • individual reversible plasticity as a genotype level bet Hedging Strategy
    Journal of Evolutionary Biology, 2021
    Co-Authors: Thomas Ray Haaland, Jonathan Wright, Irja Ida Ratikainen
    Abstract:

    Reversible plasticity in phenotypic traits allows organisms to cope with environmental variation within lifetimes, but costs of plasticity may limit just how well the phenotype matches the environmental optimum. An additional adaptive advantage of plasticity might be to reduce fitness variance, in other words: bet-Hedging to maximize geometric (rather than simply arithmetic) mean fitness. Here, we model the evolution of plasticity in the form of reaction norm slopes, with increasing costs as the slope or degree of plasticity increases. We find that greater investment in plasticity (i.e. a steeper reaction norm slope) is favoured in scenarios promoting bet-Hedging as a response to multiplicative fitness accumulation (i.e. coarser environmental grains and fewer time steps prior to reproduction), because plasticity lowers fitness variance across environmental conditions. In contrast, in scenarios with finer environmental grain and many time steps prior to reproduction, bet-Hedging plays less of a role and individual-level optimization favours evolution of shallower reaction norm slopes. However, the opposite pattern holds if plasticity costs themselves result in increased fitness variation, as might be the case for production costs of plasticity that depend on how much change is made to the phenotype each time step. We discuss these contrasting predictions from this partitioning of adaptive plasticity into short-term individual benefits versus long-term genotypic (bet-Hedging) benefits, and how this approach enhances our understanding of the evolution of optimum levels of plasticity in examples from thermal physiology to advances in avian lay dates.

  • Individual reversible plasticity as a genotype-level bet-Hedging Strategy
    2020
    Co-Authors: Thomas Ray Haaland, Jonathan Wright, Irja Ida Ratikainen
    Abstract:

    Reversible plasticity in phenotypic traits allows organisms to cope with environmental variation within lifetimes, but costs of plasticity may limit just how well the phenotype matches the environmental optimum. An additional adaptive advantage of plasticity might be to reduce fitness variance, or bet-Hedging to maximize geometric (rather than simply arithmetic) mean fitness. Here we model the evolution of reaction norm slopes, with increasing costs as the slope or degree of plasticity increases. We find that greater investment in plasticity (i.e. steeper reaction norm slopes) is favoured in scenarios promoting bet-Hedging as a response to multiplicative fitness accumulation (i.e. coarser environmental grains and fewer time steps prior to reproduction), because plasticity lowers fitness variance across environmental conditions. In contrast, in scenarios with finer environmental grain and many time steps prior to reproduction, bet-Hedging plays less of a role and individual-level optimization favours evolution of shallower reaction norm slopes. We discuss contrasting predictions from this partitioning of the different adaptive causes of plasticity into short-term individual benefits versus long-term genotypic (bet-Hedging) benefits under different costs of plasticity scenarios, thereby enhancing our understanding of the evolution of optimum levels of plasticity in examples from thermal physiology to advances in avian lay dates.