Search

In European and many African, Middle Eastern and southern Asian populations, lactase persistence (LP) is the most strongly selected monogenic trait to have evolved over the past 10,000 years 1 . Although the selection of LP and the consumption of prehistoric milk must be linked, considerable uncertainty remains concerning their spatiotemporal configuration and specific interactions 2,3 . Here we provide detailed distributions of milk exploitation across Europe over the past 9,000 years using around 7,000 pottery fat residues from more than 550 archaeological sites. European milk use was widespread from the Neolithic period onwards but varied spatially and temporally in intensity. Notably, LP selection varying with levels of prehistoric milk exploitation is no better at explaining LP allele frequency trajectories than uniform selection since the Neolithic period. In the UK Biobank 4,5 cohort of 500,000 contemporary Europeans, LP genotype was only weakly associated with milk consumption and did not show consistent associations with improved fitness or health indicators. This suggests that other reasons for the beneficial effects of LP should be considered for its rapid frequency increase. We propose that lactase non-persistent individuals consumed milk when it became available but, under conditions of famine and/or increased pathogen exposure, this was disadvantageous, driving LP selection in prehistoric Europe. Comparison of model likelihoods indicates that population fluctuations, settlement density and wild animal exploitation-proxies for these drivers-provide better explanations of LP selection than the extent of milk exploitation. These findings offer new perspectives on prehistoric milk exploitation and LP evolution., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

Pottery is one of the most commonly recovered artefacts from archaeological sites. Despite more than a century of relative dating based on typology and seriation 1 , accurate dating of pottery using the radiocarbon dating method has proven extremely challenging owing to the limited survival of organic temper and unreliability of visible residues 2-4 . Here we report a method to directly date archaeological pottery based on accelerator mass spectrometry analysis of 14 C in absorbed food residues using palmitic (C 16:0 ) and stearic (C 18:0 ) fatty acids purified by preparative gas chromatography 5-8 . We present accurate compound-specific radiocarbon determinations of lipids extracted from pottery vessels, which were rigorously evaluated by comparison with dendrochronological dates 9,10 and inclusion in site and regional chronologies that contained previously determined radiocarbon dates on other materials 11-15 . Notably, the compound-specific dates from each of the C 16:0 and C 18:0 fatty acids in pottery vessels provide an internal quality control of the results 6 and are entirely compatible with dates for other commonly dated materials. Accurate radiocarbon dating of pottery vessels can reveal: (1) the period of use of pottery; (2) the antiquity of organic residues, including when specific foodstuffs were exploited; (3) the chronology of sites in the absence of traditionally datable materials; and (4) direct verification of pottery typochronologies. Here we used the method to date the exploitation of dairy and carcass products in Neolithic vessels from Britain, Anatolia, central and western Europe, and Saharan Africa.

The gene encoding Xenopus B-Myb (XB-Myb), a protein structurally related to the nuclear protooncogene product c-Myb, is expressed in early Xenopus embryogenesis. We report on developmental alterations in the nucleocytoplasmic distribution and phosphorylation of XB-Myb in Xenopus oocytes and embryos, as well as on a negative regulatory role of the carboxyl terminus in sequence specific DNA binding. In growing oocytes and early embryonic stages the protein is primarily located in the nucleus; in the full-grown oocyte, however, it remains sequestered in the cytoplasmic compartment. Upon meiotic maturation of the oocyte, XB-Myb becomes hyperphosphorylated. Oocyte/egg isolates of XB-Myb are inhibited in their specific DNA binding activity; truncation of the carboxyl terminal region relieves this block in nucleic acid recognition. Furthermore, we have used overexpression of XB-Myb in Xenopus embryos by means of mRNA injection as an assay for gene function in vivo. Overexpression of full-length XB-Myb, not of the carboxyl terminal deletion mutant, results in an altered morphology of lateral plate mesoderm.