Laboratory selection for increased longevity in Drosophila melanogaster reduces field performance

Area of Science:

• Gerontology
• Evolutionary Biology
• Animal Behavior

Background:

• Drosophila melanogaster is a model organism for aging research.
• Longevity-selected lines often show enhanced laboratory performance and slower senescence.
• Laboratory performance may not reflect field conditions.

Purpose of the Study:

• To investigate the effects of aging, temperature, and longevity selection on fruit fly performance in a naturalistic field setting.
• To assess the ability of flies to locate a food source under varying conditions.
• To test the antagonistic pleiotropy theory of aging.

Main Methods:

• Flies from longevity-selected and control lines of different ages were released into a food-free field environment.
• Performance was measured by the ability to locate and reach a food source.
• Control flies were tested at low, intermediate, and high temperatures; selected flies were tested at intermediate temperatures.

Main Results:

• Intermediate-aged flies were generally better at resource location than younger or older flies.
• Extreme temperatures (hot and cold) accelerated age-related performance decline.
• Control lines outperformed longevity-selected lines in locating resources, indicating a potential cost to longevity in early-life field fitness.

Conclusions:

• Longevity selection may come at the cost of reduced early-life field fitness, supporting the antagonistic pleiotropy theory.
• Environmental temperature significantly influences the rate of performance decline with age in the field.
• Field performance assays are crucial for understanding the ecological relevance of aging and longevity selection.