While there has been extensive interest in how intraspecific trait variation affects ecological processes,
outcomes are highly variable even when individuals are identical: some are
lucky while others are not. Trait variation is therefore only important if it adds substantially to the
variability produced by luck. We ask when trait variation has a substantial effect on variability in
lifetime reproductive success (LRS), using two approaches: 1) we partition the variation in LRS into
contributions from luck and trait variation; 2) we ask what can be inferred about an individual's
traits, and with what certainty, given their observed LRS. In theoretical stage- and size-structured models,
and two empirical case studies, we find that luck usually dominates the variance of LRS. Even when individuals
differ substantially in ways that affect expected LRS, unless the effects of luck are substantially
reduced (e.g. low variability in reproductive lifespan or in annual fecundity), most variance in
lifetime outcomes is due to luck, implying that departures from "null" models omitting trait
variation will be hard to detect. Luck also obscures the relationship between realized LRS
and individual traits. While trait variation may influence the fate of populations, luck
often governs the lives of individuals.

#### age2SizePars.R

Data file used by IdahoIPMFunctions.R

age2SizePars.csv

#### BaselineParameterSets.Rdata

Data file used by SizeQualityFunctionsPlot.R and SizeQualityVarPartition.R

#### growPars.csv

Data file used by IdahoIPMFunctions.R

#### IdahoIPMFunctions.R

Defines functions needed by IdahoIPMLifeCycleStats.R and IdahoWinnerTraits2Plots.R

#### IdahoIPMLifeCycleStats.R

Code to generate Figs. 5 and 6

#### IdahoWinnerTraits2Plots.R

Code to generate Figs. 7 and 8

#### KittiwakeMatrices.R

Data used by KittiwakeWinnerTraitsFecSurv3.R. Demographic data are taken from Steiner, U. K., S. Tuljapurkar, and S. H. Orzack. 2010. Dynamic heterogeneity and life history variability in the kittiwake. Journal of Animal Ecology 79:436–444 and Cam, E., W. A. Link, E. G. Cooch, J.-Y. Monnat, and E. Danchin. 2002. Individual covariation in
life-history traits: seeing the trees despite the forest. The American Naturalist 159:96–105.

#### KittiwakeWinnerTraitsFecSurv3.R

Code for generating Fig. 4

#### MegamatrixFunctions.R

Defines functions needed by KittiwakeWinnerTraitsFecSurv3.R and SizeQualityVarPartition.R

#### RpartitionItero.R

Code to generate Figs. 1, 22, and 23

#### RpartitionSemel.R

Code to generate Figs. 2 and 24

#### SeedlingSurvPars.csv

Data needed by IdahoIPMFunctions.R

#### SimplePartitionSimulate.R

Code to generate Fig. 21

#### SizeQualityFunctions.R

Defines functions needed by SizeQualityFunctionsPlot.R and SizeQualityVarPartition.R

#### SizeQualityFunctionsPlot.R

Code to generate Figs. 9--13

#### SizeQualityVarPartition.R

Code to generate Figs. 10--13

#### Standard Graphical Pars.R

Defines functions needed by IdahoIPMLifeCycleStats.R, IdahoWinnerTraits2Plots.R, KittiwakeWinnerTraitsFecSurv3.R, SizeQualityFunctionsPlot.R, and SizeQualityVarPartition.R

#### SurvPars.csv

Data needed by IdahoIPMFunctions.R

#### TwoStageWinnerTraits2Plots.R

Code to generate Fig. 3

#### Utilities.R

Defines functions needed by IdahoIPMLifeCycleStats.R, IdahoWinnerTraits2Plots.R, KittiwakeWinnerTraitsFecSurv3.R, SizeQualityFunctionsPlot.R, and SizeQualityVarPartition.R

#### wPars.csv

Data needed by IdahoIPMFunctions.R

#### Compare_seedlings.R

Exploratory data analysis to compare seedlings and
others. Referred to in Appendix C.

#### fetchDemoData-allWs.R

dependency of Compare_seedlings.R, Fit_Growth_JAGS.R, Fit_Growth_Older_GAM.R, Fit_Growth_Seedlings.R, Fit_Survival_Older.R, Fit_Survival_Seedlings.R.

#### Fit_Growth_JAGS.R

Produces numbers in Table C3.

#### jags_growth.txt

Dependency of Fit_Growth_JAGS.R.

#### Fit_Growth_Older_GAM.R

Produces Figure C6.

#### Fit_Growth_Seedlings.R

Produces Figure C5.

#### Fit_Survival_Older.R

Produces numbers in Table C1.

#### Fit_Survival_Seedlings.R

Produces numbers in Table C1, produces Figure C1.

#### JAGS_tables_v3.R

Produces numbers in Table C3.

#### KittiwakeVarPartitionTable.R

Calculates the contribution of trait variation to variance in LRS and lifespan for the kittiwakes, as discussed in the first full paragraph after eq. 7.

#### ModelingW.R

Produces numbers in Table C4, produces Figure C7.

#### SizeQualityElasticityAnalysis.R

Produces numbers in Table B2.

#### TrimQuadrats.R

dependency of Compare_seedlings.R, Fit_Growth_Older_GAM.R, Fit_Growth_Seedlings.R, Fit_Survival_Older.R, Fit_Survival_Seedlings.R.

#### PartitionByW

Generates the entries in Table 2.