The Neolithic Britons originated from the Aegean

This post is a presentation of information, sourced from official publications, on the very interesting subject of Neolithization in Britain.

The Neolithic site of Silbury Hill in Wiltshire, southern England

From the paper titled “Burial practices at the Mesolithic-Neolithic transition in Britain change or continuity?“, by Emily Hellewell and Nicky Milner, 2011, we read among other things:

The transition to the Neolithic is often seen as a time of great change: domesticated animals and grain, pottery, monuments, and polished stone tools are all introduced. In Britain, this transition is usually said to occur at 4000 BC, but in recent years, research has moved towards disentangling this ‘package’ through the use of multi-scalar approaches, and some researchers have begun to think about change in terms of human time frames in order to identify variety, messiness, and localness. These approaches are coupled with scientific methods with a particular emphasis on the creation of fine-grained chronologies. The use of strict sampling methods and Bayesian statistical frameworks has enabled a better understanding of the introduction of innovations, and in the case of monument building in Southern Britain, the establishment of a gradualist model.

Other innovations such as domesticated sheep and cattle appear in the 4th millennium BC. One of the earliest dates on sheep appears to be from the site of Ascott-under-Wychwood, where sheep teeth date to 3990–3780 calBC. The most compelling evidence for early cereals come from charred cereal grain, and it has been recently argued that the introduction of grain appears at about 3800 calBC, although with ongoing dating programmes, a clearer picture may emerge. Pottery seems to appear about 4000–3700 calBC, although it has been suggested that some pottery introductions may be earlier than this at about 4200–3800 BC for certain parts of Scotland and Ireland.

When all this evidence is brought together, it is not particularly apparent whether the different aspects of the Neolithic came together or whether introductions were slightly staggered, and how this varies from region to region. However, it is very clear that in the 300–400 years at the beginning of the 4th millennium BC, great change was occurring in Britain, in many different ways.

The only articulated remains that currently exist are from the very early part of the Mesolithic in the 9th millennium BC at Aveline’s Hole and Gough’s Cave (the famous ‘Cheddar Man’). All other human bone which has been found in Britain appears to have been disarticulated. In both the Mesolithic and Neolithic periods there is evidence that the bones are being treated like animal bones, and we cannot discern a significant difference in the ways in which the human remains are being treated in the Mesolithic compared to the Neolithic.

It is not doubted that disarticulation can be the result of deliberate human treatment of the dead, but disarticulation as a treatment for the dead has received differential treatment in the literature. It is a widely accepted treatment in Neolithic studies, where sorted and manipulated human bones are interpreted as evidence for ancestral worship. However, in the Mesolithic there is little acknowledgement that disarticulated remains represent anything more than disturbed burials. This is beginning to change as new evidence from Europe demonstrates the potential of an understanding of disarticulation in the Mesolithic.

There is no doubt that the monuments such as long barrows and causewayed enclosures which appear during the 4th millennium BC, at the start of the Neolithic period, are an innovation. But it was not just monuments which were used to house the dead; caves were also used. Some studies give the impression that the use of caves is possibly reserved for ‘deviant’ burials. For instance, recent dating from sites in the Yorkshire Dales has highlighted ‘diverse treatment’ and a range of activities with regard to the deposition of human remains.

Prior to this reanalysis, the human remains from these caves were generally considered to be Late Neolithic or Early Bronze Age in date and derived from articulated burials. However, dating showed a group of five cave and rock shelters are actually Early Neolithic; the earliest known deposition of human remains in this upland region relating to Neolithic mortuary activity.

There tends to be a perception that the use of caves in the 4th millennium BC is an innovation related to an abrupt cultural transition. There is very little evidence for human remains in the Mesolithic, but most of what there is comes from a number of cave sites.

From the paper titled “Early farmers from across Europe directly descended from Neolithic Aegeans“, by Zuzana Hofmanová et al., 2016, we read among other things:

Paleogenetic studies of late hunter-gatherers (HG) and early farmers indicate a dominant role for migration in the transition to farming in central and northern Europe, with evidence of only limited hunter-gatherer admixture into early Neolithic populations, but increasing toward the late Neolithic. However, the exact origin of central and western Europe’s early farmers in the Balkans, Greece, or Anatolia remains an open question.

We present five ancient genomes from both, the European and Asian sides of the northern Aegean.

The mtDNA haplogroups of all five Neolithic individuals are typical of those found in central European Neolithic farmers and modern Europeans, but not in European Mesolithic hunter-gatherers. Likewise, the Y-chromosomes of the two male individuals belong to haplogroup G2a2, which has been observed in European Neolithic farmers; in Ötzi, the Tyrolean Iceman; and in modern western and southwestern Eurasian populations, but not in any pre-Neolithic European hunter-gatherers. The mitochondrial haplogroups of two additional less well-preserved Greek Mesolithic individuals belong to lineages observed in Neolithic farmers from across Europe; consistent with Aegean Neolithic populations, unlike central European Neolithic populations, being the direct descendants of the preceding Mesolithic peoples who inhabited broadly the same region.

In this analysis modern samples from Europe and surrounding regions are inferred to be relatively more genetically related to the Aegean Neolithic genomes than to the Neolithic genomes from Germany and Hungary.

These patterns are indicative of founder effects in the German and possibly Hungarian Neolithic samples from a source that appears to be most genetically similar to the Aegean Neolithic samples and that distinguishes them from the ancestors of modern groups.

We see the origins of European farmers equally well represented by Early Neolithic Greek and northwestern Anatolian genomes.

It is widely believed that farming spread into Europe along both Mediterranean and central European routes, but the extent to which this process involved multiple dispersals from the Aegean has long been a matter of debate.

Migration to southwestern Europe started in the Aegean but was independent from the movement to Germany via Hungary. This is also supported by other genetic inferences  and archaeological evidence. An alternative scenario is a very rapid colonization along a single route with subsequent gene flow back to Greece from Spain. Potentially, preexisting hunter-gatherer networks along the western Mediterranean could have produced a similar pattern, but this is not supported by archaeological data. Interestingly, Ötzi the Tyrolean Iceman shows unique shared drift with Aegeans to the exclusion of Hungarian Early Neolithic farmers and Late and Post Neolithic European genomes and feasibly represents a relict of Early Neolithic Aegeans.

Mixing between migrating farmers and local hunter-gatherers occurred sporadically at low levels throughout the continent even in the earliest stages of the Neolithic.

Both f4 statistics* and ADMIXTURE analysis indicate a substantial increase in hunter-gatherer ancestry transitioning into the Middle Neolithic across Europe, whereas Late Neolithic farmers also demonstrate a considerable input of ancestry from steppe populations.

The high levels of shared drift between Aegean and all available Early Neolithic genomes in Europe, together with the inferred unique drift between Neolithic Aegeans and Early Neolithic genomes from Northern Spain to the exclusion of Early Neolithic genomes from central Europe, indicate that Aegean Neolithic populations can be considered the root for all early European farmers and that at least two independent colonization routes were followed.

*NovoScriptorium: Look here for f and f4 statistics

The inside of the Neolithic houses constructed on Skara Brae in Orkney, northern Scotland

From the paper titled “Holocene fluctuations in human population demonstrate repeated links to food production and climate“, by Andrew Bevan et al., 2017, we read among other things:

Archaeological radiocarbon dates typically come from samples of bone, charred or waterlogged wood, and seeds that are taken to date specific stratigraphic events in the surviving archaeological record. When considered in large-scale aggregate, however, they also provide an anthropogenic signal of changing overall levels of past human activity and, ultimately, population. Some commentators highlight taphonomic and investigative biases in this record, but there is increasing agreement that, if these biases are controlled for and if the number of available dates is sufficiently high, an important demographic signal remains.

The overall summed distribution shows a dramatic upswing in radiocarbon dates ca. 4000–3850 BCE that coincides closely with the first arrival of Early Neolithic cereal agriculture in Britain and Ireland. Although caution is required in inferring actual population growth rates directly from rates of change in summed radiocarbon, the latter values exceed 1% during this earliest phase, are unlikely to be explained by increased fertility among farming groups alone, and therefore must be due in part to migrant farmers from the European mainland, a conclusion that is consistent with current archaeological and genetic evidence.

Evidence for an Early Neolithic boom-and-bust in the British Isles has already been noted by previous research, alongside explanations stressing a collapse due either to ecological overreach by incoming farmers or the abandonment of cereal agriculture in response to declining climate conditions.

Evidence collectively suggests quasi-periodic solar forcing of atmospheric and oceanic circulation with wider climatic consequences, associated with accentuated Siberian Highs and Icelandic Lows.We argue that these reorganizations have repeatedly exerted downward pressure on the human population in certain parts of northwestern Europe, as evident for three phases of decline in the high-resolution British and Irish archaeological radiocarbon record.

Intervening episodes of climatic amelioration may have provided good conditions for population expansion in certain areas, with the broadly simultaneous Early Neolithic colonization of southern Scandinavia, Ireland, and Britain being one probable example.

Radiocarbon-dated plant and animal food sources further provide an unusually well-resolved time series of potential changes in British and Irish food production, as long as we are careful to consider the possible confounding effects of changing human depositional practices with regard to food remains. Overall, the summed probability distribution of dates from starchy food plants (cereals and hazelnuts) broadly matches the demographic signal observed in the entire radiocarbon dataset, but in contrast the relative proportion of each plant type varies significantly.

Radiocarbon samples for individual food-animal species are fewer and encompass a wider range of meat, hide, wool, and dairying strategies, not to mention different kinds of deposition. However, comparison between the proportion of animal and plant food data suggests the greater importance of animals (as wild food) before the Neolithic and then their high visibility (as domesticated herds) again in the Late Neolithic and Early Bronze Age.

Through a data-intensive approach to the British and Irish radiocarbon evidence, we are able to provide a detailed, long-term demographic proxy that, among other things, demonstrates at least three regionally consistent episodes of population downturn. While other Holocene climate changes may also have had human impacts in this region, and other European regions need not have responded in the same way, these shared episodes of demographic change match quasi-period shifts to more unstable weather regimes in the North Atlantic and well-known solar grand minima. Furthermore, each downturn across Britain and Ireland was of varying longer-term consequence, with subsistence responses such as resource switching and food diversification that varied through time. Exogenous climatic factors appear more likely to account for these consistencies than endogenous population over-reach on its own, although both processes may well have operated in tandem.

Neolithic flint axe

From the paper titled “Ancient genomes indicate population replacement in Early Neolithic Britain“, by Selina Brace et al., 2019, we read among other things:

The transition to farming marks one of the most important ecological shifts in human evolution. The processes by which this transition occurred have been a matter of intense debate for over a century, although across continental Europe ancient DNA studies indicate a predominant role for expanding Neolithic farmer populations of mostly Aegean ancestry (Aegean Neolithic Farmers (ANF)). ANF-derived populations dispersed throughout Europe via two major routes: one along the Mediterranean and the other through Central and into Northern Europe. Both dispersing populations introgressed repeatedly with local Mesolithic foragers, which gradually increased their proportion of European Mesolithic ancestry.

Although there is universal agreement among archaeologists that there was a dramatic change in material culture in Britain around 4000 BC, there are divergent views regarding the extent to which this change was influenced by cultural or demographic processes. The British Isles lie furthest from the Aegean origin of the migrating farmers that influenced the development of the Neolithic across Europe, are geographically isolated from continental Europe by large bodies of water and had maritime climates which differ from the majority of mainland Europe—all factors that may have altered the nature of the adoption of farming. The relationship between British and continental European Mesolithic populations is also of interest, as Britain geographically abuts two genetically distinct but contemporaneous populations, Western European and Scandinavian Mesolithic hunter-gatherers (WHGs and SHGs, respectively), and could have potentially harboured ancestry from earlier (~19000–15000 BC) Magdalenian Palaeolithic hunter-gatherer populations.

Here, we report whole-genome data from 6 Mesolithic (including ‘Cheddar Man’ from Gough’s Cave, Somerset, England) and 16 Neolithic British individuals, and combine these with data from 51 previously published Neolithic British individuals to characterize the Mesolithic to Neolithic transition in Britain.

All British Mesolithic individuals cluster with Western and Scandinavian hunter-gatherers in a principal components analysis. By contrast, all directly dated individuals who post-date 4000 BC and undated individuals associated with Neolithic monuments cluster tightly near Iberian and Central European Middle Neolithic individuals.

The genomes of all British Mesolithic individuals can be explained almost entirely by WHG ancestry, the remainder (<7.3%) probably stemming from poorly matching portions of the genome. Most of the ancestry in all British Neolithic individuals could be attributed to ANFs (>56%, ~74% on average), indicating a substantial shift in ancestry with the transition to farming.

The six British Mesolithic genomes examined here are typical of WHGs, indicating that this population spread to the furthest northwestern point of Early Holocene Europe after moving from southeastern Europe, or further east, from approximately 12000 BC. This genetic similarity among British and European Mesolithic individuals spans a period in Britain (circa 8500–4000 BC) that includes the cultural transition to the Late Mesolithic and the separation of Britain from continental Europe. Our analyses indicate that the appearance of Neolithic practices and domesticates in Britain circa 4000 BC was mediated overwhelmingly by immigration of farmers from continental Europe, and strongly reject the hypothesized adoption of farming by indigenous hunter-gatherers as the main process. British farmers were substantially descended from Iberian Neolithic-related populations whose ancestors had expanded along a Mediterranean route  although with a minority portion of their ancestry from populations who took the Danubian route. The affinities we find between Neolithic individuals from the British Isles and modern individuals from France are consistent with populations sharing ancestry with Neolithic groups in Iberia moving into northern France via the Atlantic seaboard and/or southern France, mixing to a limited degree with Neolithic populations from Central Europe before travelling across the English Channel.

In contrast to other European regions, the transition to farming in Britain occurred with little introgression from resident foragers—either during initial colonization or throughout the Neolithic.

NovoScriptorium: We also firmly suggest the read of this fully related post.

The Ring of Brodgar, a Neolithic stone circle on Orkney, northern Scotland

Research-Selection for Novoscriptorium: Philaretus Homerides & Maximus E. Niles