Data from: The causes of selection on flowering time through male fitness in a hermaphroditic annual plant

Flowering is a key life history event whose timing almost certainly
affects both male and female fitness, but tests of selection on flowering
time through male fitness are few. Such selection may arise from direct
effects of flowering time, and indirect effects through covariance between
flowering time and the environment experienced during reproduction. To
isolate these intrinsically correlated associations, we staggered planting
dates of Brassica rapa families with known flowering times, creating
populations in which age at flowering (i.e. flowering time genotype) and
Julian Date of flowering (i.e. flowering time environment) were
positively, negatively, or uncorrelated. Genetic paternity analysis
revealed that male fitness was not strongly influenced by seasonal
environmental changes. Instead, when age and date were uncorrelated,
selection through male fitness strongly favored young age at flowering.
Strategic sampling offspring for paternity analysis rejected covariance
between sire age at flowering and dam quality as the cause of this
selection. Results instead suggest a negative association between age at
flowering and pollen competitive ability. The manipulation also revealed
that, at least in B. rapa, the often-observed correlation between
flowering time and flowering duration is environmental, not genetic, in
origin.