Data from: Predicting evolutionary responses to selection on polyandry in the wild: additive genetic covariances with female extra-pair reproduction

The evolutionary forces that underlie polyandry, including extra-pair
reproduction (EPR) by socially monogamous females, remain unclear.
Selection on EPR and resulting evolution have rarely been explicitly
estimated or predicted in wild populations, and evolutionary predictions
are vulnerable to bias due to environmental covariances and correlated
selection through unmeasured traits. However, evolutionary responses to
(correlated) selection on any trait can be directly predicted as additive
genetic covariances (covA) with appropriate components of relative
fitness. I used comprehensive life-history, paternity and pedigree data
from song sparrows (Melospiza melodia) to estimate covA between a female’s
liability to produce extra-pair offspring and two specific fitness
components: relative annual reproductive success (ARS) and survival to
recruitment. All three traits showed non-zero additive genetic variance.
Estimates of covA were positive, predicting evolution towards increased
EPR, but 95% credible intervals overlapped zero. There was therefore no
conclusive prediction of evolutionary change in EPR due to (correlated)
selection through female ARS or recruitment. Negative environmental
covariance between EPR and ARS would have impeded evolutionary prediction
from phenotypic selection differentials. These analyses demonstrate an
explicit quantitative genetic approach to predicting evolutionary
responses to components of (correlated) selection on EPR that should be
unbiased by environmental covariances and unmeasured traits.