Variation in environmental or genetic quality leads to phenotypic variation in condition, but how much variation in fitness is created by this variation in condition? Using Drosophila melanogaster, we manipulated condition via alternative larval diets and then tested several key factors predicted to influence how much variation in fitness results from differences in condition. Specifically, we were interested in whether male and female fitness are affected equally by condition and whether the strength of selection on condition depends on the abundance of key resources limiting the reproductive output of each sex. We measured selection on condition in alternative assay contexts that varied in the abundance of adult food (a key resource for females) or in the abundance of females (a key resource for males). Overall, selection tended to be stronger on males than females. However, selection on males was weakened when the abundance of their key resource (females) was elevated. Increasing the abundance of the key resource for females (live yeast) elevated their reproductive output as expected but did not change the strength of selection in this sex. Instead, this manipulation increased selection on males, suggesting that this environmental factor indirectly affects selection on males via their interaction with females.
Usage Notes:
Data Coding Info
Codes for other data files
Dev Timing-ALL(w-M&F)
Average development time per vial
Body mass data
Weight-ALL.xls
Adult fitness (over all 6 days)
Fitness Data-ALL.xls
Adult fitness (just day 1)
Fitness Data- Day1.xls
Adult fitnes (over days 1-3)
Fitness Data- Day1-3.xls
Adult fitness (just days 4-6)
Fitness Data- day4-6.xls