The article by Dakin and Avise examines the impact of microsatellite null alleles on parentage analysis. Null alleles, which fail to amplify in PCR assays, can introduce biases and errors in genetic studies. The authors review 233 published articles that reported suspected null alleles and discuss how these were detected and handled. They also use computer simulations to assess the effects of null alleles on exclusion probabilities and specific mating events. The results indicate that while null alleles at typical frequencies reported in the literature do not significantly affect average exclusion probabilities, they can lead to substantial errors in empirical assessments of specific mating events, particularly by causing false parentage exclusions. The study highlights the importance of considering null alleles in genetic parentage analyses and suggests strategies to minimize their impact, such as using multiple loci and requiring mismatches at more than one locus for exclusion.The article by Dakin and Avise examines the impact of microsatellite null alleles on parentage analysis. Null alleles, which fail to amplify in PCR assays, can introduce biases and errors in genetic studies. The authors review 233 published articles that reported suspected null alleles and discuss how these were detected and handled. They also use computer simulations to assess the effects of null alleles on exclusion probabilities and specific mating events. The results indicate that while null alleles at typical frequencies reported in the literature do not significantly affect average exclusion probabilities, they can lead to substantial errors in empirical assessments of specific mating events, particularly by causing false parentage exclusions. The study highlights the importance of considering null alleles in genetic parentage analyses and suggests strategies to minimize their impact, such as using multiple loci and requiring mismatches at more than one locus for exclusion.