Actually that one was probably just an outlier, considering it was just one ROH.
"Previous studies have found that, in outbred individuals, short ROH that measure tens of kb—the typical range of linkage disequilibrium (LD) in the human genome, and the typical length of a common haplotype that could be paired to form an ROH—are present at high frequencies.19 Furthermore, ROH of intermediate sizes, measuring hundreds of kb to several Mb, also occur frequently,5–7,20–29 probably as a result of background relatedness—recent but unknown kinship among the parents of sampled individuals. Extremely long ROH, measuring tens of Mb, have been observed in as many as 28%–90% of individuals from populations with higher levels of background relatedness;4–7,12,24,27 surprisingly, they have also been observed in 2%–26% of individuals in ostensibly outbred populations.4,6,7,19–22,24–31 Although some of these long ROH probably reflect recent parental relatedness, others potentially result from a lack of recombination that allows unusually long ancestral segments to persist in the general population. "
www.ncbi.nlm.nih.gov
"Previous studies have found that, in outbred individuals, short ROH that measure tens of kb—the typical range of linkage disequilibrium (LD) in the human genome, and the typical length of a common haplotype that could be paired to form an ROH—are present at high frequencies.19 Furthermore, ROH of intermediate sizes, measuring hundreds of kb to several Mb, also occur frequently,5–7,20–29 probably as a result of background relatedness—recent but unknown kinship among the parents of sampled individuals. Extremely long ROH, measuring tens of Mb, have been observed in as many as 28%–90% of individuals from populations with higher levels of background relatedness;4–7,12,24,27 surprisingly, they have also been observed in 2%–26% of individuals in ostensibly outbred populations.4,6,7,19–22,24–31 Although some of these long ROH probably reflect recent parental relatedness, others potentially result from a lack of recombination that allows unusually long ancestral segments to persist in the general population. "
Genomic Patterns of Homozygosity in Worldwide Human Populations - PMC
Genome-wide patterns of homozygosity runs and their variation across individuals provide a valuable and often untapped resource for studying human genetic diversity and evolutionary history. Using genotype data at 577,489 autosomal SNPs, we employed ...
www.ncbi.nlm.nih.gov
maybe marrying landers and other small clans isn’t enough
