Showing posts with label wheat. Show all posts
Showing posts with label wheat. Show all posts

Saturday, 20 June 2020

On the Anti-Neolithic of Cyprus

Cyprus is the first place that we know that crops and livestock were spread to by human action. This even took place before domestication. Morphologically wild wheat and barley, cattle, sheep and goat that appear wild. Cats that were presumably following mice that were stow-aways with grain stores on those early boats; early meaning ~9000 BC. But despite this very early start on the path to agriculture, Cyprus throughout the Neolithic and into the Bronze Age appears decidely unagricultural, what I might dub an anti-Neolithic. This is evident due to the accumulation of archaeobotanical and zooarchaeological evidence, that my colleague Leilani Lucas has been compiling and analyzing for several years, and which is summarized and discussed in our new Journal of World Prehistory article.

Long-term Cypriot trends  in cereals (vs. wild plants)
 Cyprus (black squares) vs. the
mainland (above). Below: proportion of deer
out of  consumed meat (below) 
Cyprus is perhaps quintessentially an island, in the sense of demonstrating evolutionary patterns that work differently from the large land areas and populations of the mainland. So years ago her work demonstrated that in terms of morphological change, domestication processes seem to be happening faster on Cyprus, with much higher rates of grain size increase in wheat. But this does not mean that wheat became quickly important or even that the overall economy was especially agricultural. Instead it appears that cereals (and other crops) remain a minor, rather than dominant, part of the economy for millennia (see left). This is in contrast to the mainland Fertile Crescent where increasingly morphological features of domestication are accompanied by a trend towards increasing use of cereals and dominance of wheats and barley out of all plant remains. If agriculture as an economic change is properly decoupled from domestication (and genetic change), then these trends clearly do not go together on Cyprus. The same is clear in the faunal record. Despite the early translocation of mammals, including livestock or potential livestock (like cattle) but also wild game (like boars and deer), it is hunted game, especially deer, that dominate bone assemblages. Cattle even plausibly go extinct and get reintroduced to Cyprus. For fully agricultural economic systems one perhaps needs to look at transformations from the Middle to Late Bronze Age, driven by Cyprus getting more central to a world system of trade, in which cultivation of "cash crop" fruits became important. In this context continued hunter-gatherer economic activities  lost ground to the food and economic production activities that transformed the wild fringes to investment agriculture.

Thus despite material culture that we class as Neolithic (and Bronze Age) the economy looks rather anti-Neolithic.

Friday, 21 September 2018

Ancient DNA in charred grains? More bad news.

No one can have missed the massive impact that ancient DNA has been having on the history of human populations and those of several domesticated animals. Bones, at least some of them, provide a nice venue for the preservation of old genomes. Plants have featured much less in this story, with estimates of 200 C) for sometime (many hours)-- does not do DNA any favours. This who have worked on ancient DNA have tended to focus on desiccated plant remains- from dry desert contexts.

A  new report on ancient DNA extraction from archaeological grains (Lundstrom et al 2018), in this case barley, from Medieval and Late Medieval Sweden, reports some good success from some dry grains from a 17th century's Bishop's burial, some success from waterlogged specimens but no success from 46 charred grains. This replicates similar attempts to get aDNA out of charred Finish barley (Lempaiainen-Avci et al 2018) and methodological trail of Nistelberger et al. 2016 who tried High-Throughput Sequencing ("shotgun sequencing") on various charred archaeological grapes, maize, rice and barley (Pictured at right), including rice provided by my lab from India, Thailand and the Comores. Nistelberger et al. concluded that charred material is likely to rarely yield sufficient reliable genetic data, a conclusion re-iterated by two Scandinavian studies.



The open question is what does this entail for older aDNA results, using "old-fashioned" methods, i.e. targeted PCR, to extract chloroplast DNA, which appears to sometimes be quite successful in differentiating indica from japonica rice for example (Castillo et al 2016), or which was used in the early days of aDNA in the 1990s to separate tetraploid from hexaploid wheats (e.g. Allaby et al 1997). Estimates then were that maybe 5% of charred grains might have some aDNA in them, but maybe those were generous over-estimates? Are we now supposed to reject such earlier work and methods out of hand? Or does it mean that methodologically, there is something about current high-throughput methods that has not solved the problem of dealing with the highly fragmented and sparse DNA that is thought to be preserved in a minority of charred remains? Reading the fine print, Nistelberger did identify a small amount of ancient DNA reads, but they regarded them as so few as to be "inconsequential". But if little is all we are left with maybe we need to change our aims to make these consequential through the questions we ask of them?

Saturday, 9 December 2017

Buckwheat origins remain elusive




Harriet Hunt and colleagues have provided a new critical assessment of data and potential data on origins of the buckwheats (Fagopyrum esculentum and F. tartaricum) in a Vegetation History and Archaeobotany article. Buckwheat is an important carbohydrate crop at high elevations in Asia, as well as parts of Japan and Europe, but it has remained quite elusive archaeobotanically.

It is absent from the many large charred seed assemblages in central China, or the charred and Fagopyrum identifications as distinct from many other Polygonaceae. Even if we accept all identifications of Fagopyrum, there are several wild taxa in this genus that will have nothing to do with the cultivtion of the crop. They consider how reliable stratigraphic dating controls are for many of pollen sequences, but even so, pollen never allows for the direct dating nor direct association with human activities that archaeobotany does.
waterlogged assemblages of the Lower Yangtze. In the Indian Himalayas where it is traditionally an important crop, finds have been few, restricted to later First Millennium BC and medieval finds in Nepal. The new review by Hunt et al has compiled evidence from archaeobotanical macro-remains, a few reported based on apparent archaeological starch remains, and the many more reports from pollen diagrams. They take a threshold of fairly high quantities in pollen diagrams, but less clear is whether one can always rely on



Distribution of wild Fagopyrum species (Campbell 1997, IPGRI)
One of their key conclusions is that the past distribution of wild Fagopyrum species, including the wild progenitor of F. esculentum, was more widespread. Extending further north, even to the north of Sichuan. This certainly seems plausible and could support a domestication in Sichuan north of where modern wild populations (in NW Yunnan) have tended to suggest domestication. They point to a few pollen cores from Shaanxi and Gansu apparently 5000 years old or more, as perhaps relating to early cultivation-- although the absence of grain finds in these regions which have had considerable archaeobotanical sampling in recent years surely calls into question the paper's tentative conclusion that cultivation had begun before 5000 BP.  Another problem with many of these pollen cores is the reliability of dating. For example, the pollen sequence at Xishanping, which was collected through an archaeological sequence, has a number of inverted radiocarbon dates, suggesting reworked residual materials, but the short (and old) chronology followed by Hunt et al. removes the out of sequence dates-- which would make sense if this were a lake core with constant sedimentation, rather than a sequence 5 varied archaeological layers. A safer, and archaeologically logical reading of the original stratigraphy (see raw data in Li et al 2007) date makes the buckwheat pollen occurrence only slightly older than 3000 BP. (The short chronology also implies that wheat was present at this Gansu site before 2600 BC, which does not fit with the accumulated evidence on wheat's arrival in Gansu (as noted already in a previous blog), especially AMS dates (see Stevens et al 2006).

A more critical reading of the dates in the sequence of the earlier pollen cores find little support for any substantial quantities of Fagopyrum pollen before around 4000 years ago, so I stand by previous inferences of domestication taking place around this period. Nevertheless from the Second Millennium BC onwards, some archaeological seeds of Fagopyrum, possible supported by starch finds points to cultivation of this crop, with a focus on west Central China and southwest China, consistent with early dispersal around the eastern front of the Tibetan plateau. Nevertheless with central and eastern China, the lower reaches of the Yellow and Yangtze basins buckwheat appears to have been absent, from macro-remains (and supported by early Chinese written sources). In this regard some of the apparent pollen reports from natural cores in the Lower Yangtze seem unlikely to represent cultivation. Despite being clearly present among the crops known in early Tibetan languages (and many related Burmic languages), and having likely been loaned from a Tibetan language into Chinese since the Han dynasty period (see Bradley 2011), buckwheat remains elusive in Asian archaeology.

This new paper by Hunt et al. provides a solid starting point for new research on buckwheat origins, with a thorough compilation of pollen and archaeobotanical evidence (in China)long with some critical thinking on the rather limited genetic data.

Thursday, 23 November 2017

The earliest wheats of Ukraine (5400 BC)

The eastern areas of Europe and their transition to the steppe that lead to Central Asia remains one of the less well-studied regions archaeobotanically. The sparseness of reliable evidence has meant that the region is sometime discussed in terms of an alternative eastern source of crops from Europe, in addition to the main thrust from Anatolia through Greece and the Balkans, and it is sometimes mooted as a region of some crop origins, such as spelt wheat. New data is always welcome, especially of a high empirical calibre, from systematic sampling and backed up by AMS dating.

New data from the Ratniv-2 site in Western Ukraine, near the eastern frontiers of the Linear Pottery (LBK) culture, has been published by Motuzaite Matuzeviciute and Telizhenko in Archaeologia Lituana. This is an important record of early crops, and as the authors point out, it clearly points to similarities to the West and Southwest in Neolithic  Europe and suggest a spread towards Ukraine from the West in the Neolithic, rather than the east. The assemblage consists of wheats, barley, flax, lentil and pea. Two direct AMS radiocarbon dates on emmer wheat grains place these assemblages between 5400 and 5200 cal.BC. Of particular interest is that the wheats here include not just einkorn and emmer but apparently at some of the socalled "new type glume wheat," which these and other authors sometimes equate with Triticum timopheevi, and 20th century relict wheat found north of the Caucasus (western Georgia). That the archaeological "new type" has the AAGG genome of timopheevi remains unproven-- although I agree it is likely. It is perhaps more accurate to regard T. timopheevi as the relict remnant of what was a once a much more diverse and widespread species of wheat, which in all likelihood originated in the Anatolia and spread through many part of Europe and east through northern Iran in the Neolithic. I have sometimes offered the name "striate emmeroid" as a descriptive alternative to  "new type", as it is hard to think of something that has been largely extinct since the Bronze Age as new, and this wheat type has been in discussion by archaeobotanists for around 20 years...

In any case, what is notable about this assemblage is that is corresponds to those crops that are most common in the Neolithic of southwest Europe, supporting the ceramic and settlement evidence that attributes to the origins of agriculture in western Ukraine to spread from the west.

Friday, 27 February 2015

Mesolithic cereal trade in Europe?

This week's Science includes in ancient sedimentary DNA study by Oliver Smith, Robin Allaby and colleagues from sediments from an archaeological site sealed beneath the English Channel, with evidence that wheat was decomposing on this Mesolithic site 8000 years ago. Such a claim is obvioulsy a big deal for archaeologists, it is counter to our accepted narrative of the introduction of cereals with Neolithic farming immigrants around 6000 years ago. No surprisingly it has received science media attention, both in Science and in New Scientist, as well as a learned commentary from Gregor Larson; and despite a busy teaching week I have been asked for comments. Here I give my full extended comment. While I agree that we really need more evidence to clinch this from additional sites, and I would prefer directly radiocarbon dated grains, I also don't think this requires a complete overhaul of what we know about the introduction of sustained farming around 4000 BC.

This paper is methodologically impressive. They have developed a robust phylogenetic approach to cautiously ID sedimentary aDNA. The deposits seem well dated and sealed by rising sea-levels. So we are left with the challenge of fitting this to our world view as archaeologists. 


This report is sure to be heavily debated, and I guess many archaeologists will reject this out of hand. But that is perhaps like the ostrich with its head in the sand. I would certainly be happier with an AMS-dated cereal grain, but this new evidence tells us we need to be actively looking for those Pre-Neolithic traded grains.

I suppose this will reopen the debate about claims for Mesolithic cereal pollen grains, which have been claimed from sites here and there in Britain and France. Most archaeologists have rightly tended to follow the critical assessment of these, represented for example by the writings of Prof Behre, a senior archaeobotanist and doyen of anthropogenic pollen indicators (e.g. Behre 2007). I expect new scrutiny of such finds, as they could also relate to a pioneer phase of small scale cereal adoption.

From Larson 2015
This find does not mean the Neolithic needs to redated. The Neolithic in Britian is well dated to about 4000 BC which sees a rapid rise in human population together with evidence for emmer wheat, barley and livestock. This follows a spread of agricultural populations, uniformly with big demographic booms across central and western Europe (e.g work by Shennan et al. in Nature Comms, 2013). This I think is still clear. But the New wheat DNA from the English channel requires us to think in terms of small scale pioneers operating beyond the frontier of farming spread and trading with Foragers, and beyond that foragers trading with each other. Mesolithic foragers were well adapted to their environments given their population density so this would not have been about trading food as needed calories but about foodstuffs that were rare, exotic and valuable. I would guess these early cereals would have been symbolically charged as exotica much like spices in much later times. In regions with obsidian we know Mesolithic populations had long distance trade networks. This new evidence suggests long distance networks also moved perishables, including edibles.

I think we can see this as on par with the food "globalization" episodes in much later prehistory, such as the Bronze Age. When sorghum and other African crops arrived in India 4000 years ago, or wheat arrived in China in the third millennium BC, these edibles proceeded any other material evidence for trade. This implies long distance small scale exchanges in exotica, including what seem to us today as mundane edibles, were highly valued, presumably in part because of the symbolic associations with distance and the exotic. I have written about this in a few places, e.g Fuller et al 2011 in Antiquity or Boivin et al 2012 in World Archaeology (blogged here).

So perhaps what we are seeing is evidence for an early Holocene equivalent-- the Neolithic grain as the tastey exotica in a the Mesolithic world

Monday, 15 July 2013

The eastern fertile crescent returns


The recent paper in Science by Riehl et al. on  the evidence for Chogah Golan has rightly garnerd wide attention (e.g. Science news; commentary by Willcox). This is a highly significant paper, which shows that the beginnings of cultivation were indeed mutlicentric within the fertile ccrescent, and it suggests that there was an independent domestication process for emmer wheat in the eastern fertile crescent in addition to that in the western fertile crescent. 


Are there surprises? Yes. The big surprise here is the emmer wheat domestication, as many have argued on biogeographical and modern genetic grounds that there should have been and eastern and western barley domestication, but this has been little considered for wheat. This is mainly because the modern distribution of wild wheats does not extend that far east and south, and thus the data from the Chogha Golan, especially the lower levels indicates that the distribution of wild wheats at the start of the Holocene/end of the Pleistocene was indeed different and more extensive than modern wild wheats. This further implies that some starts to cultivation and domestication events could have drawn on wild population that are extirpated today and therefore are not reflected in modern wild germplasm collections. Modern collection used in genetic studies are only a fragmentary representation of the past, although geneticists often fall into the trap of assuming that good wild sampling in the modern day means they have captured the wild diversity from which domestication began.

What this what we/ I suspected? Yes. I am one of a number of scholars who have been arguing for a multicentric process of parallel starts to cultivation and parallel, and protracted, domestication processes around the Fertile Crescent, i.e. De-centering the Fertile Crescent. Mostly we have argued this on contrasts between the Southwest and the north/central fertile crescent and the contrasts between morphological diversity in archaeological samples and that in modern germplasm. As the authors here note with their triticoids, they are dealing with a wild wheat type not well represented in modern collections; this is equally true of early domesticated wheats in Syria/Anatolia and even in Neolithic Europe. In the Neolithic there are extinct genetic lineages, that are morphologically distinct, that are not found in modern landraces. In other words there are several lost crops of early agriculture. 

Were things really synchronous? This remains a little unclear. The lower levels seems to have pre-domestication cultivation of barley and lentil and lost wild wheat in the equivalent of PPNA/ EPPNB time periods-- this is indeed the same period that we see this in Jordan, Israel, north and south Syria. However in the Chogha Golan there is then a break and a large minority of domesticated type emmer appears. But this is mainly in the Late PPNB (ca. 7800 BC)! By this period domesticated crops are well established at higher frequencies (usually 60-70% non-shattering spikelet bases) in western fertile crescent assemblages (mainly of einkorn wheat or barley). Emmer at Tell Aswad in Syria is ~23% non-shattering at 8300 BC and at Tell el-Kherkh in NW Syria it is 44% at ca. 8400 BC. This evolution of non-shattering (a key domestication trait) appears  slightly ahead in the west. This could mean the that 25%-domesticated assemblage at upper Chogha Golan has spread from early cultivated population elsewhere that were undergoing the gradual selection for non-shattering, or it could indicate a local process, maybe not at Chogha Golan, but nearby that simply got started a bit later. 

I would note in passing, that there was one previous suggestion of eastern emmer domestication, many years ago by Hans Helbaek in the 1960s based on rather poor samples collected by the Braidwood expedition at Jarmo in Iraqi Kurdistan in the 1950s, in which Helbaek reported intermediate types and mixtures of wild and domesticated emmer. These data were never quantified nor fully published but would potentially fit with the Chogha Golan finds. So a return to Jarmo may yet have some important archaeobotanical contributions to make.

On the whole, however, these new data offer strong support from a new dataset and a different research group for what I have been championing as a paradigm shift in agricultural origins research. From the paradigm of a rapid and singular agricultural revolution to a paradigm of protraction and entanglement that was messy and non-centric. (See, e.g. refs 2 and 19 cited by Riehl). 

Wednesday, 20 February 2013

Unravelling agricultural packages


Two recent studies, one for the west and and one for the east, illustrate how crop packages unravel and become less diverse as they spread. The spread of agriculture is so often presented as a processing of unfolding, like a blanket being stretched from the point of origin outwards. This is especially true of the spread of Near Eastern agriculture, a truly diversified crop package of cereals (multiple kinds of wheat and barley, pulses, flax, plus livestock). But when the spread of agriculture is examined in detail, it is clear that crop species and varieties drop out along the way, and those which do make it probably become less genetically diverse. A recent database analysis of Neolithic Ireland illustrates the extreme western edge of Neolithic dispersal from western Asia. Published by Meriel McClatchie (whose PhD hails from here at UCL) and various collaborators (including UCL colleague, Sue Colledge), has been published in Journal of Archaeological Science, "Neolithic farming in north-western Europe: archaeobotanical evidence from Ireland" . This study demonstrates the clear pattern of quantitative reduction in most crops in Neolithic Ireland compared with elsewhere in Europe. Emmer wheat, virtually no einkorn (and one has to ask how securely identified any einkorn was), naked barley and a bit of flax-- that pretty much sums up Neolithic Ireland, in contrast to the 8 "founder crops" that are meant to characterize the start of agricultural dispersal from the Near East. 




A similar barley and wheat (with a dash of flax) characterizes the UK early Neolithic, which like Ireland see the dramatic introduction of cereal farming shortly after 4000 BC. As recently suggested in the study of radiocarbon dates from the UK (Stevens and Fuller in Antiquity, Sept 2012). One looks forward to further Irish Analyses to see whether the collapse of Neolithic cereal farming that Chris Stevens and I see in the England and Scotland cereal data also held true in Ireland.


This parallels what we see in the East, in India for example, which has recently been mapped in the paper I co-wrote with Nicole Boivin and Alison Crowther, "Old World Globalization and the Colombian Exchange: comparions and contrast." In South Asia wheats (including glume and free-threshing), barley, several pulses and flax, all seem to be important on the Indus Valley, but this package becomes less frequent and less stable as one moves into "inner" India. Sure enough wheat and barley make it both eastwards to Bihar and south to Karnataka, but generally with a strong preference for barley few or no pulses. In China only select wheat, and rarely barley, makes any showing at all, and there wheat is quantitatively negligible. This highlights that in some cases the caloric and subsistence needs are not likely to be served by the introduced cereals from the Near East. Some years ago I made the case (Antiquity 2005) that wheat and barley in Southern India might also have been status crops, used perhaps for beer, rather than as staples. One can ask the question as to what extent some the westernmost spread of cereals in Europe was as much about preferred foodstuffs rather than subsistence necessity when wild sources like hazelnuts were still so readily used and available?

There are broad similarities but also differences in the outward spread of crops from the Fertile Crescent. While in India and China this spread is seen largely in terms of the adoption of crops by local populations, in western Europe there is evidence for a greater role of migration. While in India we tend to attribute this to the local importance of other crops, Brachiaria ramosa and mungbean in the south or rice in the Ganges, that was clearly not the case in Ireland. So I wonder if we are seeing both the effects of crossing ecological frontiers, perhaps quicker than some crops can adapt, or beyond which some crops just can not adapt. Northern Europe certainly presented great challenges to agriculture, highlighted in its extreme margins such as Norway, but also in Britain by the apparent abandonment of cereals in the later Neolithic, perhaps as temperature retreated somewhat (Stevens and Fuller 2012). Monsoon Asia was not the most suited to the Near Eastern crops either, which also points towards social rather than caloric drivers in crop spread. In another parallel with distant Britain the agriculture and sedentism in parts of the Deccan, most clearly in western Maharashtra, where wheat and barley were quite prominent, appear to have collapsed and possible were abandoned over a wide area (in this case around 1200-1000 BC at the end of the Jorwe period).

Both of these studies show the importance of larger regional datasets, in which broad patterns are often visible even with simple quantification. This broad patterns raise questions that in turn call for more intensive sampling and local studies to work out wheat is actually happening at the periods of intial adoption or abandonment. What is missing currently is more usable data from the middle, Central Asia, the Iranian plateau, etc., so that archaeobotanical databases can become truly continental across all of Eurasia.



Monday, 19 March 2012

Predomestication cereal processing and storage

The latest Antiquity includes a detailed treatment by Willcox and Strodeur of Large-scale cereal processing before domestication during the tenth millennium cal BC in northern Syria at Jerf el Ahmar. The archaeobotany of Jerf has featured large in discussion in recent years on Near Eastern domestication, with apparent evidence for an early arable weed flora (see Willcox 2012 for latest), some grain size increase (reported in Willcox 2004, discussed further in Fuller 2007), but with wild-type shattering rachides, mostly of barley and rye. Jerf has been one of the major datasets contributing to a "slowing down" of domestication, from how fast we thought it was before, and of a "de-centring of the fertile crescent." So it is important to understand just how the archaeobotanical evidence fits with the archaeology on this site, and there are some important details to digest. In this paper the present some more details on the spatial patterning of finds, especially rye and barley in relation to crop-processing (mainly later stage dehusking and preparation for grinding), and argue for possible storage in the 'public' multi-room round building in the the site. There is also discussion of rodent dropping, mainly mice (Mus), which argues for on-site cereal stores, the key context for the evolution of commensal rodents.

Friday, 9 March 2012

Pre-axumite wheat and barley preference: isotopic evidence

I seem to have overlooked this last year, but was excited to see some stable isotope results, (published last year in J. Arch Science by D'Andrea et al), from northern Ethiopian pre-Axumite  and Proto-Axumite sites (i.e. 800-100 BC). This indicate a strong tendency in human bones towards predominantly (but not necessarily) exclusively C-3 plant diet, i.e. such crops as wheat and barley, but with limited C-4 input. This is of interest since Sorghum, tef and finger millet, all of which might expect to have been around are C-4 plants. So the mystery deepens as to the antiquity of these taxa in agriculture in this region-- or at least they were not very important. If memory serves there is some evidence for tef from around this period (but mainly later)-- treated in some detail by D'Andrea (and blogged previously), where as the earliest finds of finger millet and Sorghum are later and Axumite Also there is an important contrast with the domestic fauna, which have a distinctly different diet form the people. Cattle and donkey have a strongly C4 signature suggesting grazing or foddering mainly from the savannah grasslands. Sheep, goat and gazelle fall in between suggesting C4 grazing mixed with browsing of C3 shrubs etc.


Thursday, 8 March 2012

Wheat museum

It was hard to resist the image at right, of a museum dedicated to wheat, designed with an ear on top. This web site, of an old press release (July 2005), was just brought my attention by a colleague. It claims to celebrate "the earliest known wheat culture" (well that was not in Turkmenistan) the Anau culture (which is pretty late in the Neolithic), and the archaeology of Pumpelly (turn of the last century), who is credited with the first explanatory model of agricultural origins that attributed agricultural origins to climatic change. Good to have that immortalized somewhere. Later announcements indicate that this museum was also to become a national germplasm bank for wheat, which seems a good thing.

Wednesday, 7 March 2012

Dating archaeobotanical treasure troves from Armenia and Peru

The arrival of a new issue of Antiquity is always a welcomed event. The issue that arrived in my mail box this week a particular trove of treasures of an archaeobotanical sort. Not so much for archaeobotanical reports as such (the only such is the study by Willcox and  Strodeur on the details of Jerf el Ahmar), but for tantalizing new information of sites that have exceptional plant assemblages, or that one expects will in the future, like the Han era Pompeii, Sanyanzhuang (blogged below). Two sites, which are well-known for exceptional preservation are the Areni-1 cave complex in Aremenia (Areshian et al in Antiquity), left, and Huaca Prieta mound in coastal peru, below right (Dillehay et al.). 
     Areni made the news a couple of years ago for its early leather footwear, from ca. 3500 BC (Pinhasi et al in PLOSone), but it also has dessicated plant remains of many sorts: emmer and free-threshing wheat and barley, of course, but also lentil, grasspea, grapes, plums, walnuts, almonds and pears. How many of these fruit and nuts represent species that were available wild in the region, were under cultivation or introduced as cultivars still needs to be clarified. The site has produced features indicating on-site wine production, so presumably grapes were cultivated, from at least, from around 4000 BC. 4000 BC is associated with the earliest material reported so far, but the site still has much to yield to excavation, presumably including earlier material. Late samples from the past 2000 years include cotton and textiles.

     Huaca Prieta also boasts exceptional archaeobotanical preservation, and with a long sequence it provides information that suggests the chronology of cultivar introductions in this region. Few plants are likely to be native here and so their introductions point earlier cultivation and domestication elsewhere. This includes Cucurbita sqaush, avocado and lima bean at 7000-5500 BC, and thereafter the appearance of chillis and bottlegourds. Cotton cultivation was established around 4800 BC, and after 4500 BC maize was added to the repertoire. This is some of the best dated and documented early maize in South America, detailed of which were published earlier this year (see previous blog). Peanut, sweet potato and quinoa also come from later levels. Full details are not yet published but some summary can be found in the on-line supplement. This site has also produced coca leaves, indicating the long traditions of chewing this drug plant. Dillehay and colleagues reported the earliest for use of this drug, back to ca. 6000 BC, from elsewhere in northern Peru about a year and half ago, also in Antiquity. Intriguingly this drug plant, plausibly from across the Andes, appeared to already have domestication features at this date.

Saturday, 11 February 2012

Another IWGP theme:Food Globalization in Prehistory Across Eurasia


Another proposal for  a thematic session at IWGP 2013, Thessaloniki, has come through. This is not from me, but from Cambridge so interest should be sent as appropiate to some of the Cambridge archaeobotanical post-doc (website), Geidre Motuzaite Matuzeviciuit or Liu Xinyi. This lab has been active on the research of temperate millets for a while (previous blog), including recognition of immature Panicum.

This topic obviously relates to the discussion article that this group published in the last World Archaeology, on food globalization in prehistoric Eurasia (which I have not gotten around to commenting on previously in this blog.

Here is the precis for their session: Food Globalization in Prehistory Across Eurasia. Chair of a session: Prof. Martin K. Jones

 A variety of crops that originated in China or central Asia, such as the Chinese millets and buckwheat, had appeared in Europe by the 5th millennium BC, while by the end of the second millennium BC, the south-west Asian crops, wheat and barley, had reached several parts of China.

There are some striking features of that early phase of food globalisation, features that relate both to the crop plants themselves and to the societies that utilised them. A series of later episodes of globalisation, from the Classical period onwards, involve exotic fruits, vegetables and spices. The earlier phase, however, is manifested in evidence for staple sources of grain starch, the cereals, and the 'pseudo-cereal' buckwheat. 

We would like to invite papers or poster on current archaeobotanical and genetics studies that aim to establish when and how that early globalisation of staple foodstuffs happened, what it meant for human societies in very different parts of Eurasia, and what it meant for the plants upon which they relied for food.

Monday, 6 February 2012

Taking agriculture to the edge: Arctic Norway

We usually think about the spread of Neolithic agriculture as an inevitable, progressive march, as well-adapted cereal systems, for example Wheat and Barley from Near East, are extended along favoured soils and river valleys, for example along Europe's Danube. While this is our standard wave-of-advance model, and it may have much going for it for middle latitudes, we often pay less heed to the limits of agriculture, and past attempts to push those limits. A new study on the introduction of agriculture to northern Norway provides a nice example. Per  Sjögren and Johan E. Arntzen report in Vegetation History and archaeobotany the limited macro-remains evidence, pollen evidence and some settlement data on the earliest agriculture on Kveoy Island, at nearly 69 degrees North. Here agriculture was rather more marginal. There is doubtfully any agriculture before about 1000 BC, but then there is a Late Bronze Age establishment of fields. The seed record suggests mainly barley, but surprisingly a little bit of wheat (emmer?) also appears to be present. Like the Early Neolithic emmer in Britain (including Scotland), this tends to hint at some cold adapted landraces in early prehistory that we would be hard pressed to find in the relict emmer populations of today (in hot Mediterranean climates, Ethiopia, South India, etc.). This agriculture however may well have failed and there is a suggested hiatus in the last centuries BC/early AD, before a Late Roman Iron Age re-establishment of farming. This may be an extreme example, but I suspect as we look we will find more and more regions in which farming was given up, whether due to local climate swings or simply to choosing something less marginal.

Sourcing the 'lost Saraswati' river: new geological evidence

Recently published on-line in Geology  is a paper which might not appear on the surface to be very archaeobotanical, but which is important for thinking about the past agriculture of the Indus valley. This is by Clift et al (2012) on "U-Pb zircon dating evidnece for a Pleistocene Sarasvati River and capture of the Yamuna River". This paper provides sources for the headwater sediments in the various rivers of the Indus system based on zircon finger-printed (geological source dating in the 1000s of millions of years). These dated source profiles in turn are stratified in the Pleistocene and Holocene river sequences which have been dated by OSL. These river systems include the now extinct Ghaggar-Hakra river, often equated with the 'lost Saraswati" of Indian epic. The paper shows that while the Ghaggar-Hakra used to be much larger in the Pleistocene, drawing on the headwaters that now feed the  Yamuna, tha Yamuna had begun to flow  east into the Ganges before the End of the Pleistocene, and therefore well before the start of Harappan urban societies. Throughout the Holocene, including the Harappan period this river was fed only by seasonal monsoon rain in the east. This rain-fed Ghaggar-Hakra was  active until after 4.5 ka and was then covered by dunes before 1.4 ka. What this means is that the Ghaggar-Hakra, unlike any of the major Indus tributaries, was not fed by snow melt, which begins in Spring and may be unpredictable, but was entirely reliant on swelling its banks from the summer monsoon. This means it would have been an ideal river for winter crop agriculture, along the lines of the Nile flood regime which is keyed to the Blue Nile's monsoon source, with sowing of wheat and barley in Oct.-Nov. as the monsoon flood began to recede to leave behind a rich floodplain. These could then be left to mature until harvests in March or April, without fear of early snowmelt floods ruining crops. It really should come as no surprise then that so many Harappan Bronze Age sites concentrated in this valley. Nevertheless as monsoons gradually weakened (already underway during the Harappan period) with the flood water source retreating eastwards, and the Thar desert expanding, the valley became gradually drier and eventually choked with desert sands. This, however happened in Iron Age or post-Iorn Age times, so thus there is no basis for correlating any catastrophic shift in the Ghaggar-Hakra with the end of the Harappan civilization-- a notion which has often appealed to archaeologists.
[edited for typos 9.2.2102 DF]


For further discussion of the sedimentological results by geologist blogger: see here

Wednesday, 11 January 2012

Obscure crops of 2011 and an obscure book

I am ever the fan of the obscure crop, the "lost crop", or the highly local. I have drawn attention previously to the forgotten oil-millet of Taiwan, and tef-- which is obscure to those less familiar with Ethiopian agriculture-- a couple of years ago. I thought it might be interesting as part of a end of 2011 review, to compile some of the more obscure crops that got archaeobotanical attention in publications this past year.

1. Abutilon theophrasti,  socalled "China jute" or velvetleaf, was reported in quantity from a Hungarian Late Neolithic site in a storage jar (5th millenium BC) by Medovic and Hovrath. This is the only archaeological evidence for its cultivation that I know of, and it highlights the mystery surrounding where this crop comes from. This species can grown for bast fibre, similar to jute, but fruits and seeds are also edible. This find tend to lend support to the hypothesis of an eastern Mediterranean origin rather than an in China with early dispersal to Europe before 4000 BC.

2. Argan (Argania spinosa)-- the argan oil tree (or "goat-turd oil" as I have often heard it called), has its first(?) archaeological record from Southern Morocco, published by Marie-Pierre Ruas Margareta Tengberg & al. in Vegetation History and Archaeobotany. They also provide an excellent ethnographical description (and photos) of the gathering and processing: fruit eaten by goats; stones cleaned out of goat droppings, and pressed for oil... one of the priciest oils out there (if not the most pricey). Hunting for unadulterated bottles of the stuff was a recurrent theme in the markets of Fez or Meknes when I was on excavation in Morocco some years ago.  Even small 50mL bottles, when you can find them, in London can set you back nearly 10 pounds. But its is a wonderfully distictive oil for salad dressing for, better, bread-dipping...

But for those into obscure and lost crops, a nice obscure book is Threatened Crop Sepcies Diversity by Korous Khoshbakht and Karl Hammer (a prolific researcher on crop diversity!). Actually published in 2010, in Tehran by Shahid  Behesti University Press, it is unlikely to turn up in your local book store (but there is a PDF to be found from an Iranian site). I was lucky enough to find one with a Christmas card from Prof. Hammer in my post a few weeks ago, a real holiday treat. What a gem, with short account on obscure wheats, from Triticum karamyschevii, to forgotten millets such as Digitaria sanguinalis, to farmer preserved plants such as the banana relative Musella lasiocarpa, which is apparently now extinct in the wild, but it remains in cultivation as a raw fibre material and pig fodder by ethnic minorities like the Yi. Moringa hildbrantii, an endemic of Madagascar, appear to survive only in hedges and planted fences as an ornamental and medicinal. It includes nice summaries of the extinct Silphium of ancient Libya, or the more recent extirpated domesticated forms of German Pellitory (Anacyclus officinarum) grown in parts of Europe, such as Germany, as a medicinal up to the 19th century, but apparently now extinct in its domesticated form, but survived by it likely wild progenitor A. pyrethrum. 

Nevertheless, other obscure and endangered crops are missing (such as  the oil-millet of Taiwan  or Khasi hills millet, Digitaria cruciata, or South Indian browntop millet, Brachiaria ramosa). Also missing are some of the archaeobotanically well-known lost crops, the striate emmeroid wheat of prehistoric Europe, first published by Jones et al 2000, for example, or the Bronze Age Greek oilseed forms of Lallementia (Jones and Valamoti 2005), or the domesticated sumpweed of North America, Iva annua var. macrocarpa, extinct from the native cultivars of the midwest by the time serious European records became available, but clearly recognized archaeologically (e.g. Yarnell 1972).

Loss of diversity of cultivars is undoubtedly a tragedy of our time, but it also is not entirely new; diversity of cultivars has been being gained and lost since agriculture began.

Friday, 9 December 2011

De-centering the fertile crescent

The Near Eastern "fertile crescent" is the classic centre of origin for domesticated plants. Although when James Breasted coined the term (1906) he was thinking about the beginnings of agrarian civilizations in Egypt and Mesopotamia. The term become subsequently linked to Gordon Childe's notion (1935) of the "Neolithic Revolution" and with Vavilov's "centres of origin" idea, and the Fertile Crescent became, in archaeological argot, the centre of agricultural origins par excellence. In another classic paradigm-setting paper Jack Harlan used the Fertile Crescent as representative of a "centre" of origin, a focused area in which a package of crops was domesticated together, opposed to his notion of a "non-centre" of diffuse origins of crops that were not-packaged and spread out in domestications in space and time, of which the sub-Saharan savannah was perhaps the classic Harlanian exemplar. Within "centres" the Neolithic was meant to be a revolution, domestication rapid, and hunter-gatherers transformed to village farmers in one process. However, the evidence for this has been gradually unravelling for the Near East, with domestication-- the evolution of domestication syndrome traits in crops-- taking place quite slowly (3000-4000 years), and taking place not in a focused area, as a package of crops, but spread out and with as many dead-end proto-domesticates as paths into the crops and farming systems we know for later prehistory or history. In other words, there was no Neolithic Revolution as such but evolutionary processes, in the slow Darwinian sense, in which many incremental changes and transformations only added up to something revolutionary in retrospect, after millennia (some 150 to 200 human generations) of small steps.


You can find the case for this made in the December World Archaeology in my joint paper with George Willcox and Robin Allaby "Cultivation and domestication had multiple origins: arguments against the core area hypothesis for the origins  of agriculture in the Near East" which is a companion piece with our in press paper in the Journal of Experimental Botany  "Early agricultural pathways: moving outside the ‘core area’ hypothesis in Southwest Asia". Both are responses precipitated by publication late last year by Abbo et al. of a re-iteration of the "core area" view of  a tightly focused area where a single package of "founder crops" was domesticated rapidly. Such a view requires the assumption that archaeobotanical evidence is false fossil record, a poor reflection of actual domestication processes, i.e. that the gradual changes that appear in systematic archaeobotanical evidence, are somehow misleading or mistaken. I find this hard to accept-- perhaps because I am a practicing archaeobotanist and regard the preserved grains and rachises of prehistoric crops as our most material record of what these plants were like and how they were used in the past-- but also because recent years have seen increasing sampling and sample size and it is the increase in these data, and the detail with which they have been studied, that most points to the more gradual evolutionary processes. In addition, the "core area" view delimits a smaller number of founder crops and sets aside (or even rejects implicitly) the presence of past cultivars and domesticates now extinct, from the Abu Hureyra rye, 2-grained einkorn, the "new type" emmer ('striate emmeroid'), or the Gilgal oats-- all species which are the product of careful efforts of archaeobotanists to document the material remains of past crops and not to assume that all crops that ever were must still exist today. These constitute the "lost crops" of the Fertile Crescent just as much as Iva annua is a lost crop of the American midwest.  Coupled with the genetics of known crops that support multiple "domestication pathways" (such as in barley, emmer, pea, probably one-grained einkorn), the Fertile Crescent as a whole was host to something like 20 domestication "events," only a fraction of which can be localized in any one sub-area of the Fertile Crescent or can be expected to be present in modern germplasm collections. With this number of domestications and their diffuse nature across the Near East, the Fertile Crescent as a whole starts to look like a Harlanian "non-centre". On the level of individual crops and domestication events there may well be many centres of origins but in terms of regions it look increasingly like all were non-centres. The closer one looks for a core centre, the blurrier it becomes. 

Last year I declared in General Anthropology, a paradigm shift in agricultural origins research. Perhaps rather pretentious, but it remains the case that domestication appears to be a slower process as we gather more evidence, and there is evidence for more places of domestication around the world (North America, South India, separate North and South China, various parts of Africa, New Guinea, to name a few). This year I have put my money where my mouth is, and brought out a number of contributions looking at domestication processes in the Near East in particular and in comparison to the best documented crops from elsewhere (mainly in the Old World). This includes attempting to objectively calculate rates of domestication in terms of phenotypic units, the darwin and haldane, reported in terms of more general conclusions-- that domestication was slow and not somehow special compared to other forms of evolution-- in the journal Evolution (Purugganan and Fuller), and unpacked with more consideration of the variation across crops in the Near East and elsewhere in Vegetation History and Archaeobotany (Fuller, Asouti, Purugganan). See also the updated rachis data of Tanno and Willcox (2011)phenotypic change may differ in adjacent geographical contexts, and in particular that there appear to be in island effects on Cyprus, where grain size change was sped up (Lucas, Colledge, Simmons & Fuller). A careful consideration of the hard evidence, such as the essay assaying the southern Levant (Asouti & Fuller), shows that even for the Fertile Crescent we still lack the evidence we need to be clear about domestication processes in particular micro-regions, early cultivation or when agriculture emerged (keeping in mind that cultivation, domestication and agriculture are really different things from among the many transitions that gradually came together). We also note that there is alot more work to be done on the species that were important wild food stuffs, which were abandoned as cereal agriculture took off, the small-seeded grasses and legumes, wild nuts and nutlets-- evidence in other new archaeobotanical datasets such as that from Jordan (el-Hemmeh) of White et al. (which reports important evidence for how barley was harvested prior to domestication) or 3 sites from the northern and eastern Fertile Crescent (SE Turkey and Iran) of Riehl et al.. Of course as the role of many wild foods along side pre-domesticated cereals gains recognition, the difficulty of being clear what was a likely weed as opposed to gathered become acute-- an issue discussed in a short paper by Willcox on early weeds. Another recent paper out of London (Wollstonecroft, Hroudova, Hillman & Fuller on Bolboschoenus) illustrates an example of challenges that still confront archaeobotanical identification, and the the potential ecological and dietary implications of refining these to species level, in this case for the sedge Bolboschoenus glaucus.
 Most of these papers, now available on-line for a forthcoming Vegetation History and Archaeobotany issue on the Near East which will illustrate the revised (and more diverse) understanding of the precursors of Fertile Crescent agriculture: the tides seem to have turned on the simpler core area paradigm!

Thursday, 22 July 2010

Emmer wheat synthesis of genetics & archaeology

Both genetics and archaeobotany provide vantage points of reconstructing the early history of crops, where and how they originates, and how they spread. There has been a growing recognition in both fields that some of our previous conclusions were false truths, based on simplistic assumptions. There has been a small, but growing trend, for some true interdisciplinary synthesis, of archaeobotanists teaming up with geneticists to write the history of crops, and a new example comes from the journal Genetic Resources and Crop Evolution, "Geographic distribution and domestication in wild emmer wheat (Triticum dicoccoides)" in which archaeobotanist George Willcox teams up with geneticists (including Ozkan, Salamini and Kilian) to provide an updated compilation of what is know about Emmer and what it might mean for multiple starts of cultivation, gradual domestication, but the possible predominance of one domesticated line at the end of the process. It generally points towards a much more complex picture genetically and biogeographically, and it recognizes the incompleteness of sampled datasets, including the range of modern emmer landraces and wild populations as representatives of what would have been there in the past. This paper hasn't solved all the mysteries of the origins of agriculture in the Near East, nor of emmer, but it represents serious progress through a conversation between archaeology and genetics, rather than just talking past each other.


Friday, 9 July 2010

Gansu Province survey archaeobotany

A recent issue of the Chinese Science Bulletin contains an archaeobotanical paper from what appears to be a new archaeobotanical research group. An ChengBang et al. report evidence from survey archaeobotany in Qinan and Li counties, and as such follows in the path laid by flotation as part of field surveys published previously from the Yiluo Survey (Lee et al 2007) and the Ying Survey (Fuller and Zhang 2007; see also our GIS study in Journal of Archaeological Science). This new study is based on 96 samples, from something like about 40 sites (although this is not entirely clear). Unfortunately the full dataset is not published, and we are given a glimpse of it through summary data presented as bar chart of absolute counts of Panicum and Setaria grains. Not the most informative means of comparing across sites and periods with very different sample sizes. The presence of rice (7 grains in the Late Yangshao) and wheat and barley (from the Western Zhou period) are only referred to in the text description. No reference is made to any other species, whether pulses, fruits or weeds. One novel addition to the study was a stable carbon isotope study of the millet grains, which shows that Setaria tends to have a somewhat higher value than Panicum, as expected since although both are C4 plants they have different forms of the C4 mechanism. A novel technique but the results are still close enough that this is unlikely to replace morphological identification! While it is nice to see more archaeobotanical research being carried out in China, the attention to only cereals, the lack of discussion of archaeological context (it is even unclear which sites numbers are which period), a less helpful method of quantification, and the lack of full details makes this study a rather frustrating addition.

The arrival of wheat in China

The extensive set of direct dates, on the largest early assemblage of wheat and barley in China, provides important new evidence on the arrival of West Asian crops, and western stimulus, into China. Rowan Flad, Li Suicheng, Wu Xiaohung and Jimmy Zhao, have recently reported new archaeobotanical evidence and AMS dates from the Gansu corridor site of Donhuishan in short article in The Holocene, "Early wheat in China: Results from new studies at Donghuishan in the Hexi Corridor." Importantly, the evidence includes the first large assemblage of wheat rachis remains. These provide the first clear confirmation of what has long been taken for granted, that the early wheat in China is only hexaploid bread wheat, leaving the eastern margins of tetraploid naked wheats (durum) somewhere in central Asia and to the south in India. This article also provides an updated review of all the early wheat finds that have been published from China.

In my version of their map (left), I have colour-coded wheat reports by broad period. First of all, it can be seen that finds line up along the eastern line of the classical silk road, running through the Gansu corridor and along the Lower Yellow river basin. It should noted that while the earliest finds are all attributed to 2500-2000 BC, or even more than 2500 BC in the case of Xishanping, none of these earliest finds is directly AMS dated. The case on Donghuishan reported by Flad et al., provides a warning call against putting too much faith in single or few or associated dates, as the earlier evidence from Donghuishan has suggested the wheat could be closer to 2500 BC rather than the 1600-1500 BC age indicated by numerous dates, including 4 directly on barley (but not wheat). Nevertheless it still seems plausible that wheat and barley entered China by ca. 2500 BC, even if the wheat crop did not take off until closer to 2000 BC. This period of arrival ion China is paralleled by the adoption from the west also of sheep, cattle and probably copper metallurgy (with a possible parallel spread to Southeast Asia-- as argued recently by Whyte and Hamilton). The counter current was provided by Chinese millets, as both Panicum miliaceum and probably Setaria italica arrive in northwestern India around this period, and Panicum is also reported in Yemen (ca. 2200 BC) and in Sudan by ca. 1700 BC. On the dispersal of westwards and southwards through the Indus to Arabia and Nubia, see discussion the paper "Cattle, Crops and Commensals" that I recently published with Nicole Boivin in the French periodical Etudes Ocean Indien [pdf]. I have also argued that japonica rice followed this route west from the Yellow river and in India (see discussion in my article in the recent rice issue of Archaeological and Anthropoloigical Sciences)

Interestingly the barley from Donghuishan, like that from Xishanping, is notable since most sites in China that have yielded wheat have lacked barley. This indicates that the adoption of wheat went through a strong cultural filter in which is was only wheat rather than wheat and barley that was adopted in much of central China. This provides a curious contrast from other regions of Asia, whether west Asia, central Asia of South Asia where wheat and barley are almost always found together archaeologically. In India these two winter cereals are also often found with evidence for pulses crops like lentils, peas or chickpeas. None of these Southwest Asia crops appears to have made it into prehistoric China. Thus the diffusion of crops into (and out of) China was selective process of cultural choice.