Extended Data Fig. 5 |. Y chromosome haplogroup frequency changes over time.
Estimated frequency of the characteristically British Y chromosome haplogroup R1b-P312 L21/M529 in all individuals for which we are able to make a determination and which are not first-degree relatives of a higher coverage individual in the dataset. Sample sizes for each epoch are labeled at the bottom, and we show means and one standard error bars from a binominal distribution. The frequency increases significantly from ~0% in the whole island Neolithic, to 89±4% in the whole island C/EBA. It declines non-significantly to 79±9% in the MBA and LBA (from this time onward restricting to England and Wales because of the autosomal evidence of a change in EEF ancestry in the south but not the north). It further declines to 68±4% in the IA, a significant reduction relative to the C/EBA (P=0.014 by a two-sided chi-square contingency test). There is additional reduction from this time to the present, when the proportion is 43±3% in Wales and the west of England (P=5×10−6 for a reduction relative to the IA), and 14±2% in the center and east of England (P=3×10−32 for a reduction relative to the IA).