The article discusses the estimation of relatedness using genetic markers in vertebrate populations. It compares two methods for estimating relatedness: one based on genotypic correlation and another based on genetic similarity. The study uses Monte Carlo simulations to evaluate the accuracy of these methods under various conditions, including different numbers of groups, group sizes, and allele frequencies. The results show that the genotypic correlation method provides a more accurate estimate of relatedness, especially when the number of loci is increased. The study also highlights the limitations of genetic similarity as a measure of relatedness, particularly when the frequency of the common allele is not near 0.5. The authors conclude that the correlation technique is preferred for estimating mean relatedness within groups, although it does not provide information on the variance of relatedness among groups. They suggest that a calibrated genetic similarity index could be used in cases where sufficient genetic information is available, or that relatedness may be estimated from a reconstructed genealogy obtained by maximum likelihood methods if limited pedigree information is available. The study emphasizes the importance of using multiple loci and large groups to achieve precise estimates of relatedness.The article discusses the estimation of relatedness using genetic markers in vertebrate populations. It compares two methods for estimating relatedness: one based on genotypic correlation and another based on genetic similarity. The study uses Monte Carlo simulations to evaluate the accuracy of these methods under various conditions, including different numbers of groups, group sizes, and allele frequencies. The results show that the genotypic correlation method provides a more accurate estimate of relatedness, especially when the number of loci is increased. The study also highlights the limitations of genetic similarity as a measure of relatedness, particularly when the frequency of the common allele is not near 0.5. The authors conclude that the correlation technique is preferred for estimating mean relatedness within groups, although it does not provide information on the variance of relatedness among groups. They suggest that a calibrated genetic similarity index could be used in cases where sufficient genetic information is available, or that relatedness may be estimated from a reconstructed genealogy obtained by maximum likelihood methods if limited pedigree information is available. The study emphasizes the importance of using multiple loci and large groups to achieve precise estimates of relatedness.