The evolution of intergenerational discounting in offspring quality

Area of Science:

• Evolutionary biology
• Life-history theory

Background:

• Intergenerational effects link parental actions to descendant success.
• Conflicts can arise between short-term and long-term measures of reproductive success.
• Existing life-history theory prioritizes long-term success, potentially overlooking evolutionary dynamics.

Purpose of the Study:

• To investigate how evolutionary changes affect intergenerational effects.
• To model the interplay between parental investment and the rate of evolution.
• To re-evaluate predictions of selection outcomes when traits evolve over time.

Main Methods:

• Utilized numerical simulations and analytical models.
• Incorporated intergenerational effects and evolutionary change into models.
• Examined parental investment per offspring and total reproductive effort as investments in future generations.

Main Results:

• The rate of evolutionary change was found to dictate the level of parental investment.
• Higher mutation rates and sexual reproduction (vs. parthenogenetic) correlated with lower parental investment per offspring and reduced total reproductive effort.
• Ancestor-descendant investment levels respond to intergenerational genetic relatedness.

Conclusions:

• Preexisting life-history theory may be insufficient when traits evolve rapidly.
• Evolutionary dynamics significantly influence optimal strategies for parental investment.
• The study reveals a novel mechanism linking genetic relatedness across generations to investment strategies.