Parental Optimism and Progeny Choice: When is Screening for Offspring Quality Affordable

Area of Science:

• Evolutionary biology
• Behavioral ecology
• Parental investment strategies

Background:

• Parental overproduction of offspring can be driven by various fitness incentives.
• One hypothesis, progeny choice, suggests parents create excess offspring to select the best.
• This selection may involve filial infanticide or sibling rivalry to enhance average offspring quality.

Purpose of the Study:

• To explore the conditions under which the progeny choice hypothesis is evolutionarily advantageous.
• To analyze the trade-offs between offspring quality enhancement and the costs of overproduction and sibling competition.
• To identify ecological and genetic factors that favor or disfavor progeny choice mechanisms.

Main Methods:

• Theoretical analysis of parental investment strategies.
• Modeling the costs and benefits of progeny choice under different scenarios of sibling rivalry.
• Comparative analysis of species exhibiting varying degrees of offspring competition and parental manipulation.

Main Results:

• Progeny choice is cost-effective only if overproduction and sibling competition costs do not outweigh quality improvements.
• Fair sibling competition maximizes quality discrimination but can be costly.
• Parentally managed competition reduces costs but impairs quality assessment.

Conclusions:

• Progeny choice mechanisms are favored in species with low sibling rivalry costs, large, evenly matched cohorts, and high genetic variation.
• This strategy is less suited for species with asynchronous hatching or significant parental manipulation of offspring advantages.
• The effectiveness of progeny choice depends on balancing the benefits of genetic selection against the costs of intensive early-stage competition.