Monthly Archaeology Round-Up: April

Bronze Age Drugs, Swahili Genetics, Viking America, Natives Horses, Benin Bronzes & Mongolian Yak Dairy

It’s been a little while since I published a round-up and plenty has happened. This month I’ve picked a good blend of discoveries, but certainly a theme amongst them is refutation of older narratives. The origins of Native American horses, Swahili genetics, Viking exploration and more all point to the validation of oral histories, traditional texts and long-dismissed archaeology.

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Early dispersal of domestic horses into the Great Plains and northern Rockies

Everybody knows that Native Americans rode horses, and everybody knows that Europeans introduced them to the continent, creating a new niche of life on the Great Plains. What nobody seems entirely sure of is when, where and how the different tribes first got access to horses. The traditional story runs that horse stocks were carefully controlled by the Spanish until the Great Pueblo Revolt of 1680, which resulted in Spanish defeat and expulsion from New Mexico. It has long been reasoned that this event led to horses being captured and traded far and wide, kick-starting the remarkable transition from settled to mobile life for so many Native peoples.

However, a new collaborative project between anthropologists and members of various Native nations, including the Oglala Lakota, Comanche and Pawnee, have reassessed horse remain collections dating to the earliest known finds, to find new data - and did they ever. Using DNA, stable isotopes, radiocarbon dating and zooarchaeological techniques, the team were able to show that at least three horses found within Native archaeological contexts predated the Pueblo Revolt. Bayesian radiocarbon modelling produced an estimated median date of 1544 for the first indigenous use of horses, over a hundred years before the traditional date. Isotopes and dental studies showed that horses were being managed away from European settlements prior to the Revolt, likely being foddered with local maize, and DNA proved they came from Eurasian sources.

However, our new data—which align with some Comanche and Shoshone oral accounts (51) (materials and methods section 7)—suggest that ancestral Comanche had already integrated horse raising, ritual practices, and transport into their lifeways at least a full half century before their southward migration, effectively moving to the southern plains as horse herders. Once in the southern plains, the Comanche were able to marshal these advantages, along with their herding and equestrian skills, to build an empire on horse and bison trade by the middle of the 18th century CE

This seems set to help rewrite and shed light on the murky period of early Plains society formation, filling in the blanks where horse adoption seemed to generate a rapid shift towards raiding, slaving and expansion.

Entwined African and Asian genetic roots of medieval peoples of the Swahili coast

Long time readers of my work will be familiar with a scholarly dynamic or drama that is playing itself out over many areas of archaeology and history. The general pattern goes something like ‘original claim to origins, claim dismissed by 20th century academics, original claim validated by genetics’. We’ve seen this with regard to steppe migrations, the Bell Beakers, the Anglo-Saxons, and this month we witness the same event on the African east coast.

The Swahili civilisation is a general term for that coastal and maritime set of empires running roughly from Somalia down to Mozambique, linking native African cultures with Islamic, Persian, Austronesian, Portuguese and British influence. One of the founding ‘myths’ of this civilisation-zone is the descent of the Shirazi people from Persian traders and settlers around the year 1000 AD. This oral history was written down in the Kilwa Chronicle, in both Arabic and Portuguese. However, post-war academics have long disputed the claim that this settlement and intermixing ever took place. A quick quote from researcher J. D. van Allen’s 1982 work The Shirazi Problem in East African Coastal History should suffice to give a flavour:

What I hope has been achieved in this essay is to bury once and for all that East African Shirazis must be ultimately descended from immigrants from the Persian Gulf. It is clear that, even if there were such immigrants and some of them played an important role in the early days, the Shirazi phenomenon itself is a purely African one which could have arisen without them. The Shirazi legend is not a folk-memory of an actual migration but a typical myth of primary origins, which has survived long and spread far because it has been used to bolster the dominance of an important group. The Shirazis were not the only people on the East African coast to utilise such a legend as part of their magic.

You can probably guess what is coming. Ancient DNA was extracted from 80 individuals from a number of coastal towns and settlements dated to between 1250 and 1800 AD. The genomes generated showed conclusively that immigration and intermixing with migrants from Persia had most certainly taken place. In fact, the maternal DNA produced a majority L* haplogroup, one which is restricted to sub-Saharan Africa - whilst the paternal DNA was a mixture of J2, G2 and a few R1a - a combination which points to the Persian Gulf. The paper is well worth reading for more details, but the main takeaway should really be that decades of linguistic, architectural, archaeological and historical theory has been largely destroyed overnight by these findings. Once again, careful houses of cards were built to dismiss ‘colonial’ era interpretations and even local oral history, and have been shown up to be a farce.

Direct evidence of the use of multiple drugs in Bronze Age Menorca from human hair analysis

Archaeology and forensics share a number of methods and aims, and not for the first time we see the application of forensic techniques in revealing an ancient puzzle. Drug detection through hair analysis is commonplace in competitive sports, prisons and other modern institutions, and in archaeology it has been used to varying degrees of success with mummies and other well-preserved remains. Here we have an unusual set-up - locks of hair, cut off and placed into tubes and small containers in a bronze age cave.

The burial and cult cave of Es Càrritx, in Menorca (Balearic Islands), was discovered in 1995. Used as a collective burial site between 1400 and 800 BC, over 200 bodies have been discovered. A strange ritual began around 1100 BC, where relatives and friends or specialists started cutting the hair of the deceased, staining it red with dye and sealing it in little antler and wooden vessels. Only a few people received this treatment, the magic words to the archaeologist, as it suggests some kind of preferential mortuary rites.

Container with the hair strands from Chamber 5

Running the hair samples through powerful chromatography and spectroscopy machines, the Spanish and Chilean team discovered three exciting compounds - ephedrine, atropine and scopolamine. These alkaloids were present in small amounts (circa 300 picograms/milligram), but enough to have been consumed for a while before death. Contrary to some arguments that these plants must have come from the New World, there are enough alkaloids present in the native plants to have a powerful effect. Datura stramonium, Hyoscyamus albus, Ephedra fragilis, Papaver somniferum and Mandragora automnalis have all been found on other sites, and together would yield the three compounds. To quote from the paper:

Rather than just being hallucinogens, atropine and scopolamine belong to the group of deliriant drugs, i.e., they induce delirium characterized by extreme mental confusion, strong and realistic hallucinations, disorientation, alteration of sensorial perception, and behavioral disorganization¹²⁴. Out-of-body experiences and a feeling of alteration of the skin, as if growing fur or feathers, are usually reported¹²⁵.

Whether these were ritual specialists or small groups of elites/society members or just people suffering from different illnesses, we don’t know. Late bronze age religion and the relationship between secret societies, shamans, warrior cults and powerful elites is not at all clear, but its incredible to have the analytical tools to begin to unravel it.

Benin Bronzes were crafted of metal from an unexpected place

Few colonial era objects inspire passions like the Benin Bronzes, the collection of statues and plaques created by the Kingdom of Benin between the 13th and 18th centuries. The story of how they were acquired by the British military after the 1897 Expedition, which resulted in Benin City being sacked, is well known. What has remained a mystery is the source of the metal used to make them, since Nigeria had no access to such quality metals. Although known as the ‘bronzes’, most of the metal pieces are made from brass, the origin of which has been much debated. After contact with the Portuguese in the 15th century, metalworkers began to incorporate brass ingots called ‘manillas’, which were a kind of currency shaped like a bracelet. Millions of them were sent to West Africa over the centuries, and it has long been assumed that the bronzes were made from recycled manillas.

A paper from an international team of researchers has finally pinned down the location. Using manillas recovered a number of shipwreck sites, the group used trace element and lead isotope analysis to reveal that lead-zinc ores from the German Rhineland were the principal source of the metal. The researchers argue that, although English and Scandinavian manillas also existed at the time, Benin’s metalworkers were deliberately selecting those from the Rhineland, recognising them as a superior product.

Norse Greenlanders found to have imported timber from North America

The Viking exploration of the New World is always a popular topic and much remains to be discovered about their exploits. One contentious source of evidence is the saga record, the heroic accounts of Norse deeds and stories. Two in particular describe the voyages and adventures in North America - Grænlendinga saga and Eiríks saga rauða - the Vinland Sagas. Academic trends have ebbed and shifted on how accurate the sagas are, and how much truth can be gleaned from them. As I’ve discussed before, a number of scholars (Walter Goffart, Andrew Gillett and Michael Kilukowski in particular), dismiss all Norse and Germanic literature as having no value to archaeology. Therefore any empirical verification of the sagas helps to build a counterpoint that we should take stories, sagas, tales, oral histories and legends seriously as sources of possible truth.

One such verification appeared this month, in the form of timber. The Norse settlements in Greenland (Eystribyggð and Vestribyggð) were a precarious secondary colony, heavily dependent on trade through Iceland with northern Europe. Ivory, walrus skins, polar bears and tusks went one way, and iron ore, timber and some foods the other. Good timber for housing, barrels, furniture, animal shelters and boats was of the utmost importance, and the sagas identify ‘Markland’ in North America as a crucial source of wood. In a detailed study of 8552 pieces of wood from Greenlandic Norse settlements, the researcher Lísabet Guðmundsdóttir identified the following proportions: 35% of the wood came from native Greenlandic trees (downy birch, Greenland mountain ash, grey willow and so on), 50% came from driftwood (larch, spruce, pine, fir etc) and the remainder came from imports. Some of the imports came from Europe, but some were confirmed as American by process of elimination. Since neither hemlock nor Jack pine could have been accessed by Norse explorers in any other way but travelling to North America, it confirms the point in the sagas that many voyages were driven by the need to find timber.

Permafrost preservation reveals proteomic evidence for yak milk consumption in 13th century Mongolia

Permafrost is nature’s gift to archaeologists, sealing and preserving even the most trace evidence for those with the technology to recover it. This month we are looking at yaks, and yak dairy. When and where the yak was domesticated, and how they ended up in Mongolia are still up for debate. One reason for this is that dairy proteins, which can be extracted from dental calculus, are often very similar between related species, making it impossible to distinguish between them. In fact the commonly discovered milk protein, beta-lactoglobulin, is so similar between cows and yaks that it differs by one single amino acid in the final tryptic peptide of the protein sequence. Near perfect preservation is therefore needed to accurately identify the species.

The final amino acid sequence of the beta-lactoglobulin protein compared between related species. Note the single difference between the yak and cattle sequences.

Enter the elite burials of the Khorig cemeteries - situated within the permafrost ridgelines of the Khovsgol mountains in northern Mongolia:

The cemeteries of Khorig I and II span a period beginning just before the unification of the Mongol Empire (1206 CE) and through the Yuan Dynasty period (1271–1368 CE)^42,43. Lavish grave goods indicate that many of the individuals buried in the cemeteries were elite members of society, with only one other aristocratic cemetery identified for this period in Mongolia.

Extracting proteins from the dental calculus of 11 buried individuals, the team from the Max Planck Institute and the National Museum of Mongolia (amongst others), managed to show that 80% of them had consumed milk, meat and blood from donkeys, horses, sheep, cattle and yaks. This puts the earliest date for yak milk consumption at around 1270 AD, almost certainly it was consumed earlier than this, but no doubt more evidence will be found in the future.