3.2 Genetic diversity, inbreeding and mean kinship
Measures of the mean number of alleles, effective number of alleles, expected and observed heterozygosity and allelic richness were all lower in the three King Island scrubtit subpopulations than they were within all of the Tasmanian scrubtit subpopulations, except the Tasman Peninsula (Table 1, Figure S10). FIS confidence intervals overlapped zero in all subpopulations (Figure S10). Mean individual level inbreeding coefficients calculated using the modified Visscher’s method were higher in the three King Island scrubtit populations than all of the Tasmanian scrubtit populations, again except the Tasman Peninsula (Figure 5a). The majority of King Island scrubtits plotted towards the higher end of individual inbreeding estimates across the entire sample (Figure 5b). The mean number of private alleles within the King Island scrubtit subpopulations were within the range of those of the Tasmanian scrubtit, but the number increased three-to-sixfold when King Island scrubtits were analysed separately (Table 1). Within population mean kinships for the King Island populations when analysed as the island populations only, reflected on average a first cousin relationship (~0.0625; Table 1). However, when within population mean kinships for King Island populations were analysed with all the Tasmanian mainland populations, the within populations mean kinship for the King Island populations reflected on average a full-sibling relationship/parent-offspring (~0.2500; Table 1). Samples from the Tasman Peninsula also reflected a mean kinship of a full-sibling/parent-offspring relationship, whilst the North East and South Bruny Island samples reflect a mean kinship of a half-sibling relationship (Table 1).
Table 1: Sample sizes by molecular sex (F/M) and population genetic parameters for the King Island and Tasmanian scrubtit. Parameters shown are number of alleles (A), number of effective alleles (AE), SNP expected heterozygosity (HE), SNP observed heterozygosity (HO), Wright’s inbreeding coefficient (FIS  ± 95 % CI), mean individual inbreeding coefficient (IIC), allelic richness (AR), mean private alleles (PA) and within population mean kinship (mean ± SE) for King Island populations only, and for all subpopulations. See Table S6 for estimates with standard errors.