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Data from: First evidence of deviation from Mendelian proportions in a conservation program

Cite this dataset

Grueber, Catherine et al. (2021). Data from: First evidence of deviation from Mendelian proportions in a conservation program [Dataset]. Dryad.


Classic Mendelian inheritance is the bedrock of population genetics and underpins pedigree-based management of animal populations. However, assumptions of Mendelian inheritance might not be upheld in conservation breeding programs if early viability selection occurs, even when efforts are made to equalise genetic contributions of breeders. To test this possibility, we investigated deviations from Mendelian proportions in a captive meta-population of the endangered Tasmanian devil. This marsupial population is ideal for addressing evolutionary questions in conservation due to its large size, range of enclosure types (varying in environmental conditions), good genomic resources (which aid interpretation), and the species’ biology. Devil mothers give birth to more offspring than they can nurse in the pouch, providing the potential for intense viability selection amongst embryos. We used data from 140 known sire-dam-offspring triads to isolate within-family selection from population-level mechanisms (such as mate choice or inbreeding), and compared observed offspring genotypes at 123 targeted SNPs to neutral (i.e. Mendelian) expectations. We found lower offspring heterozygosity than expected, and subtle patterns of differential effects across a gradient of management intensity from zoo-like enclosures to semi-wild environments for some loci. Meiotic drive or maternal-foetal incompatibilities are consistent with our results, although we cannot statistically confirm these mechanisms. We found some evidence that maternal genotype affects annual litter size, suggesting that family-level effects are driven by differential offspring mortality before birth or during early development. Our results show that deviations from Mendelian inheritance can occur in conservation programs, despite best-practice management to prevent selection.