Data from: Resolving the conundrum of inbreeding depression but no inbreeding avoidance: estimating sex-specific selection on inbreeding by song sparrows (Melospiza melodia)

Inbreeding avoidance among interacting females and males is not always observed despite inbreeding depression in offspring fitness, creating an apparent ‘inbreeding paradox’. This paradox could be resolved if selection against inbreeding was in fact weak, despite inbreeding depression. However, the net magnitude and direction of selection on the degree to which females and males inbreed by pairing with relatives has not been explicitly estimated. We used long-term pedigree data to estimate phenotypic selection gradients on the degree of inbreeding that female and male song sparrows (Melospiza melodia) expressed by forming socially-persistent breeding pairs with relatives. Fitness was measured as the total numbers of offspring and grand-offspring contributed to the population, and as corresponding expected numbers of identical-by-descent allele copies, thereby accounting for variation in offspring survival, reproduction and relatedness associated with variation in parental inbreeding. Estimated selection gradients on the degree to which individuals paired with relatives were weakly positive in females, but negative in males that formed at least one socially-persistent pairing. However, males that paired had higher mean fitness than males that remained socially unpaired. These analyses suggest that net selection against inbreeding may be weak in both sexes despite strong inbreeding depression, thereby resolving the ‘inbreeding paradox’.

Female Annual Reproductive Success Data

This file contains data required for the analyses of female annual reproductive success in relation to the female's mean kinship with the socially-paired males with which she made each breeding attempt across her lifetime. This analysis is presented in the paper's Supporting Information.

FemaleARSDryadFinal.txt



Female Kinship Data

This file contains the raw data underlying the calculation of each female's mean kinship with the socially-paired males with which she made each breeding attempt.

FemaleKDryadFinal.txt



Female Lifespan Data

This file contains data required for the analyses of female lifespan in relation to the female's mean kinship with the socially-paired males with which she made each breeding attempt across her lifetime. This analysis is presented in the paper's Supporting Information.

FemaleLifeDryadFinal.txt



Female Lifetime Reproductive Success Data

This file contains data required for the analyses of female lifetime reproductive success in relation to the female's mean kinship with the socially-paired males with which she made each breeding attempt.

FemaleLRSDryadFinal.txt



Male Annual Reproductive Success Data

This file contains data required for the analyses of male annual reproductive success in relation to the male's mean kinship with the socially-paired females with which he made each breeding attempt across his lifetime. This analysis is presented in the paper's Supporting Information.

MaleARSDryadFinal.txt



Male Kinship Data

This file contains the raw data underlying the calculation of each male's mean kinship with the socially-paired females with which he made each breeding attempt.

MaleKDryadFinal.txt



Male Lifespan Data

This file contains data required for the analyses of male lifespan in relation to the male's mean kinship with the socially-paired females with which he made each breeding attempt across his lifetime. This analysis is presented in the paper's Supporting Information.

MaleLifeDryadFinal.txt



Male Lifetime Reproductive Success Data

This file contains data required for the analyses of male lifetime reproductive success in relation to the male's mean kinship with the socially-paired females with which he made each breeding attempt.

MaleLRSDryadFinal.txt

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