The consequences of the Neolithic transition in Europe—one of the most important cultural changes in human prehistory—is a subject of great interest. However, its effect on prehistoric and modern-day people in Iberia, the westernmost frontier of the European continent, remains unresolved. We present, to our knowledge, the first genome-wide sequence data from eight human remains, dated to between 5,500 and 3,500 years before present, excavated in the El Portalón cave at Sierra de Atapuerca, Spain. We show that these individuals emerged from the same ancestral gene pool as early farmers in other parts of Europe, suggesting that migration was the dominant mode of transferring farming practices throughout western Eurasia. In contrast to central and northern early European farmers, the Chalcolithic El Portalón individuals additionally mixed with local southwestern hunter–gatherers. The proportion of hunter–gatherer-related admixture into early farmers also increased over the course of two millennia. The Chalcolithic El Portalón individuals showed greatest genetic affinity to modern-day Basques, who have long been considered linguistic and genetic isolates linked to the Mesolithic whereas all other European early farmers show greater genetic similarity to modern-day Sardinians. These genetic links suggest that Basques and their language may be linked with the spread of agriculture during the Neolithic. Furthermore, all modern-day Iberian groups except the Basques display distinct admixture with Caucasus/Central Asian and North African groups, possibly related to historical migration events. The El Portalón genomes uncover important pieces of the demographic history of Iberia and Europe and reveal how prehistoric groups relate to modern-day people.

Scandinavia was one of the last geographic areas in Europe to become habitable for humans after the Last Glacial Maximum (LGM). However, the routes and genetic composition of these postglacial migrants remain unclear. We sequenced the genomes, up to 57× coverage, of seven hunter-gatherers excavated across Scandinavia and dated from 9,500–6,000 years before present (BP). Surprisingly, among the Scandinavian Mesolithic individuals, the genetic data display an east–west genetic gradient that opposes the pattern seen in other parts of Mesolithic Europe. Our results suggest two different early postglacial migrations into Scandinavia: initially from the south, and later, from the northeast. The latter followed the ice-free Norwegian north Atlantic coast, along which novel and advanced pressure-blade stone-tool techniques may have spread. These two groups met and mixed in Scandinavia, creating a genetically diverse population, which shows patterns of genetic adaptation to high latitude environments. These potential adaptations include high frequencies of low pigmentation variants and a gene region associated with physical performance, which shows strong continuity into modern-day northern Europeans.

Adiponectin is an adipokine with insulin-sensitising actions in vertebrates. Its receptors, AdipoR1 and AdipoR2, are PAQR-type proteins with 7-transmembrane domains and topologies reversed that of GPCR's, i.e. their C-termini are extracellular. We identified three adiponectin receptor homologs in the nematode C. elegans, named paqr-1, paqr-2 and paqr-3. These are differently expressed in the intestine (the main fat-storing tissue), hypodermis, muscles, neurons and secretory tissues, from which they could exert systemic effects. Analysis of mutants revealed that paqr-1 and -2 are novel metabolic regulators in C. elegans and that they act redundantly but independently from paqr-3. paqr-2 is the most important of the three paqr genes: mutants grow poorly, fail to adapt to growth at low temperature, and have a very high fat content with an abnormal enrichment in long (C20) poly-unsaturated fatty acids when combined with the paqr-1 mutation. paqr-2 mutants are also synthetic lethal with mutations in nhr-49, sbp-1 and fat-6, which are C. elegans homologs of nuclear hormone receptors, SREBP and FAT-6 (a Δ9 desaturase), respectively. Like paqr-2, paqr-1 is also synthetic lethal with sbp-1. Mutations in aak-2, the C. elegans homolog of AMPK, or nhr-80, another nuclear hormone receptor gene, suppress the growth phenotype of paqr-2 mutants, probably because they restore the balance between energy expenditure and storage. We conclude that paqr-1 and paqr-2 are receptors that regulate fatty acid metabolism and cold adaptation in C. elegans, that their main function is to promote energy utilization rather than storage, and that PAQR class proteins have regulated metabolism in metazoans for at least 700 million years.

Authentication of ancient human DNA results is an exceedingly difficult challenge due to the presence of modern contaminant DNA sequences. Nevertheless, the field of ancient human genetics generates huge scientific and public interest, and thus researchers are rarely discouraged by problems concerning the authenticity of such data. Although several methods have been developed to the purpose of authenticating ancient DNA (aDNA) results, while they are useful in faunal research, most of the methods have proven complicated to apply to ancient human DNA. Here, we investigate in detail the reliability of one of the proposed criteria, that of appropriate molecular behavior. Using real-time polymerase chain reaction (PCR) and pyrosequencing, we have quantified the relative levels of authentic aDNA and contaminant human DNA sequences recovered from archaeological dog and cattle remains. In doing so, we also produce data that describes the efficiency of bleach incubation of bone powder and its relative detrimental effects on contaminant and authentic ancient DNA. We note that bleach treatment is significantly more detrimental to contaminant than to authentic aDNA in the bleached bone powder. Furthermore, we find that there is a substantial increase in the relative proportions of authentic DNA to contaminant DNA as the PCR target fragment size is decreased. We therefore conclude that the degradation pattern in aDNA provides a quantifiable difference between authentic aDNA and modern contamination. This asymmetrical behavior of authentic and contaminant DNA can be used to identify authentic haplotypes in human aDNA studies.