Extended Data Fig. 8: Geographic and genomic distributions of northwestern European hunter-gatherer ancestry among British and Irish Neolithic individuals.

a, Geographic distribution of northwestern European hunter-gatherer introgression in Britain and Ireland across 103 Neolithic samples. Box plot (Tukey’s method) highlights four outliers, three from the Early-to-Middle Neolithic of Argyll and one from Ireland (designated Parknabinnia675 (PB675)). The next highest value is also from Parknabinnia (individual PB754). b, The same D-statistic run on separate chromosomes for individuals of sufficient coverage (n = 86). Outlying individuals are marked for each chromosome. Irish outliers follow the same shape and colour key as in Fig. 1. Outliers who are also outliers in the box plot in a are marked in bold. c, Box plot (Tukey’s method; n = 86) of sample standard deviations across the chromosomes for the same D-statistic. Four outliers with high variance across the chromosomes are marked, including three samples from Parknabinnia, two of whom are also top hits in a. d–f, Haplotypic affinities of imputed Irish and British Neolithic individuals (n = 47) to Irish hunter-gatherers, relative to other northwestern European hunter-gatherers (Bichon, Loschbour and Cheddar Man). Colour and shape key follows Fig. 1. The outlying individual PB675 shows a preference for Irish hunter-gatherer haplotypes in all measures. Regression lines are shown with 95% confidence interval shaded (sample size = 47). PB675 shows a higher-than-expected number of Irish hunter-gatherer haplotypes (d), has the highest overall hunter-gatherer haplotypic length contribution, with a ratio skewed towards Irish hunter-gatherers (e) and displays the longest average length of Irish-hunter-gatherer haplotype chunks (f).