Data from: Pedigree-based inbreeding coefficient explains more variation in fitness than heterozygosity at 160 microsatellites in a wild bird population

Although the pedigree-based inbreeding coefficient F predicts the expected
proportion of an individual's genome that is identical-by-descent
(IBD), heterozygosity at genetic markers captures Mendelian sampling
variation and thereby provides an estimate of realized IBD. Realized IBD
should hence explain more variation in fitness than their pedigree-based
expectations, but how many markers are required to achieve this in
practice remains poorly understood. We use extensive pedigree and
life-history data from an island population of song sparrows (Melospiza
melodia) to show that the number of genetic markers and pedigree depth
affected the explanatory power of heterozygosity and F, respectively, but
that heterozygosity measured at 160 microsatellites did not explain more
variation in fitness than F. This is in contrast with other studies that
found heterozygosity based on far fewer markers to explain more variation
in fitness than F. Thus, the relative performance of marker- and
pedigree-based estimates of IBD depends on the quality of the pedigree,
the number, variability and location of the markers employed, and the
species-specific recombination landscape, and expectations based on
detailed and deep pedigrees remain valuable until we can routinely afford
genotyping hundreds of phenotyped wild individuals of genetic non-model
species for thousands of genetic markers.