Saturday, 20 July 2019

Panicum domestication and early sedentism in Northeast China

For the past decade the Xinglongwa culture of eastern Inner Mongolia (Liao River valley) has been regarded as a likely cultural context for the domestication of common millet (Panicum miliaceum), on the basis of significant quantities of Panicum grains associated with some of the many houses excavated at the site of Xinglonggou (see, e.g. Zhao 2011). Recently, new excavations by a Chinese-Israeli collaborative team (with some London archaeobotanists) explored parts of two new small settlement sites of this period, Jiajiagou (5950-5700 BC) and Tachiyingzi (5550-5450 BC), including intensive flotation, have been published this week in PLOSone. At both sites a single dwelling was excavated and sampled, and the archaeobotanical data indicate a predominance of wild plant foods, including walnuts, apricot endocarps, hawthorns, Phellodendron, but Panicum miliaceum is also present is small quantities-- 16 in total at both sites, with more and higher ubiquity at the later site. Most of these Panicum grains are more elongate then plump, with size and L/W ratios that correspond better to Panicum miliaeceum subsp. ruderale, known today as a weedy species but probably descended from, or at least comparable to the origins wild progenitors. We take this to suggest that grain size/shape was still under going evolution over the course of the 6th millennium BC, and thus it may not have been finished evolving into its domesticated form. This fits the now recurrent pattern of protracted domestication processes in cereals (explored previously when "de-centering the fertile crescent", and demonstrated more statistically in Allaby et al "Geographic mosaics and changing rates of cereal domestication").

These data, along with those from Xinglonggou indicate that while Neolithic sedentism had been established in Northeast China by the early 6th Millennium BC, the evolution of domesticated Panicum miliaceum and the establishment of agricultural economies still took rather longer. Another conclusion of the paper is that sedentism and this domestication process took place during stable and quite conducive climatic conditions. This argues against the hypothesis that domestication in this case was driven by climatic stress, or that it should be linked to major climatic fluctuations that characterize the start of the Holocene (a hypothesis promoted by Bar-Yosef 2011, amongst others)

It is worth noting that the later site (Tachiyingzi) also has the presence of a few Setaria italica and S. viridis, and a couple more plump grains (pictured above). While none of these grains was directly dated there is some possibility that more fully domesticated grains will prove to be intrusive. Amongst the direct AMS dates, on wild foods, four proved to be 6th Millennium BC, but one date on fragments from lotus seeds turned out to be intrusive and late Bronze Age. This highlights the need for more direct dating of crop remains, a point highlighted by recent debates over the arrival of wheat in Late Longshan China, for which numerous false alarms have been dismissed via direct radiocarbon dating (see "Assessing the occurrence and status of wheat in late Neolithic central China: the importance of direct AMS radiocarbon dates from Xiazhai").      

So the case for a millet domestication in Northeast China in strengthened. This does not rule out other dometciation centres-- which there must have been for Setaria italica at least, and perhaps Panicum milieceum. Domestication can be regarded as taking place alongside and after the emergence of sedentism, but further data are needed to better document this, and to assess the extent to which initial cultivation  of wild millet was linked to the shift to sedentism or not. 

Saturday, 13 July 2019

In Memoriam, 'Leo' Aoi Hosoya (1967-2019)

photo by Dorian Fuller
It is with sadness that I report the passing of an archaeobotanical colleague and friend, Leo Aoi Hosoya, who passed on 10 July 2019. Our condolences go first to her family, her husband and daughter. Many archaeobotanists at the IWGP held in Lecce in June 2019 will recall her paper presented in absentia, that began with an amusing video message from Leo. Sadly her health did not improve. "Leo" was actually her adopted English name, based on her zodiac sign, as she had thought that her Japanese name, Aoi, might be difficult to manage for the English. So as Leo she became known to many of us and she played a role in international research not just through her own work (on archaeobotany in Japan and China) but through her place in international networks and networking, facilitated by good humour, friendliness and lack of negativity; she was always contagiously optimistic.

IWGP 1995, Innsbruck: left to right:
Gardar Gu├░mundsson, Mary Anne Murray,
Lydia Zapata, Leonor Pena-Chocarro,
Ann Butler and Leo Hosoya
 [Photo courtesy M.A. Murray]

Aoi was born 14 August 1967. Her global journey could be said to have begun with her post-graduate degrees at Cambridge (from 1992), including her MPhil and PhD. I met her when I started my Master's there in 1995 and we were lab-mates once I started my PhD in 1996. Together with Marco Madella and Victor Paz we formed a group of young researchers interested in various parts of Asia, concerned with rice, millets, etc. and how research approaches that were well-established in Europe, such as analysis of arable weed floras and crop-processing could be translated into new approaches to understanding the Asian past. Leo's work towards her PhD, focused on the Yayoi period in Japan, was very much pioneering, addressing the patterns of crop processing in rice and millets for the first time. She was among the very first archaeobotanist to pull rice spikelet bases out of flotation samples, which we later realized would be essential for studying rice domestication. But her knowledge of Japanese ethnohistorical and archaeobotanical sources also opened my mind to the rich traditions of use and processing of acorns, which very much went on to influence my thinking about nut use in the Neolithic. Her Phd was completed in 2002, but published in a revised monograph-like article in Senri Ethnologica in 2009 [PDF], its title's phrase"Sacred Commonness" reflects her strong interest in relating the mundane of crop processing and agriculture to greater symbolic and social patterns that run through past societies. Her interest in theorizing the social while working through empirical science remains inspiring. Her time as a PhD student in Cambridge brought her to her first International Work Groups for Palaeoethnobotany in 1995 and 1998. (See also the in memoriam of Prof. Martin Jones here).
Leo Hosoya, Dorian Fuller, field trip
during the IWGP 1998, Toulouse, France

For several years, Leo was a post-doctoral research associate at the Research Institute for Humanity and Nature (Chikyukan) in Kyoto. There she was part of the team of a project "Agriculture and Environment Interactions in Eurasia- A 10,000 year history" directed by Prof. Yo-Ichiro Sato, where I was lucky enough to be an invited researcher in 2007 and 2009. She was also part Junzo Uchiyama's Project "NEOMAP", which was looking comparatively on the Neolithic traditions throughout northeastern Asia. Those were optimistic times for international collaborations, new empirical archaeobotanical research and integration across various datasets. For me, Leo was ever a guide to parts of Japan and Japanese archaeology, that I would have otherwise missed. From visits to sites in Hokkaido or Aomori (such as Komakino, below left, or Kiusu, shown at the top), to a memorable trip over the mountains from Kyoto to visit the Torihama shell midden museum to chase down measurable bottlegourds (in 2009; sadly I could find no photos of anything but gourds and woodend tools from that trip- although it resulted in one joint publication on East Asian gourds). It was also a time of many food-centered parties held at the guest house of RIHN.
Leo Hosoya at back left. 

It was at this time that both Leo and I came independently to collaborations with the Zhejiang Institute on the archaeobotany of Tianluoshan, an exciting Neolithic discovery in the Lower Yangtze region made in 2004. Over the years of 2006 and 2007 we made a few tips each to the site to work on sieving and sorting soil samples for plant remains to document the extensive wild food use at the site and the many rice spikelet bases, which lead to recognition of an assemblage in which rice was still undergoing evolution of domestication (another joint publication in Science). This work built on Leo's early efforts both of pulling rice spikelet bases from flotation samples that started in her PhD and of understanding acorn use, which she usefully summarized in this 2011 article.
from Left: Xugao Chen, Ying Zhang, Yunfei Zheng, Dorian Fuller
Ling Qin, Leo Aoi Hosoya, Guoping Sun

While in Kyoto, Leo took a lead roll in organizing some targeted archaeobotanical meetings, bringing together archaeobotanists, geneticists and ethnographic perspectives, first on rice (held in Kyoto in 2009), and later on millets held in Tokyo in 2012. Both lead to special journal issues edited by Leo, on rice, and millets. Subsequent meetings on rice that were held in Beijing and London very much grew out of that first Kyoto meeting. In 2009 she also came to London on a British Academy Darwin researcher's award, and conducted some preliminary work on the processing and detoxification of peach and apricot seeds, plausibly used as nuts or famine foods in Neolithic China (article pdf here).

In subsequent years she became involved in ethnoarchaeological work on rice storage in Bali (2016), which contributed to her ongoing wholistic approach to understanding rice, not just as an agricultural product but as part of social and culinary reorientation of society, as part of what she referred as the "routine-scape" (2014).  Most recently she has been one of the sub-project leaders of a major Japanese-lead international project on "Integrated Studies on Rice-based civilization" for which she has taken a multi-proxy approach to understanding of cooking pots have been used and how this changes over the course of the intensification of rice use in the Lower Yangtze Neolithic an the Yayoi in Japan. She presents some of this work in a chapter published in honour of Martin Jones' retirement, and at the symposium held in Cambridge in Nov. 2018; her chapter "Rice and the Formation of Complex Society in East Asia: Reconstruction of Cooking Through Pot Soot- and Carbon-deposit Pattern Analysis" can be downloaded as part of the book Far from the Hearth (2019). Her in absentia presentation for 2019 IWGP was on the same project, and its holistic approach to an archaeology of cooking is an inspiration for the rest of us to keep working and to enjoy a good meal and a shojiu in Leo's memory.
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 I can add photos that are  emailed to me.
Rice archaeology symposium, Kyoto, 2009

Leo Hosoya chairing presentations at Rice Symposium

Leo Hosoya (centre) during discussions on the Rice symposium, Kyoto 2009. Prof. Sato (speaking)

Early rice symposium, Peking University, May 2011. Leo Hosoya in front row (second from right)

Early  Rice symposium dinner, from Left: Alison Weisskopf, Heejin Lee, Yuchao Jiang, Michele Wollstonecroft, LEO HOSOYA, Peter Bellwood, Mrs. Bellwood, Mukund Kajale 

The exCambridge Contingent at the International Millets symposium, Tokyo Museum, 2012.
From Left: Victor Paz, Marco Madella, Leo Hosoya, Dorian Fuller, Martin Jones, Xinyi Liu

More photos from the Tokyo meeting (courtesy of Tania Valamoti)

June 2008: Junzo Uchiyama, Leo Hosoya, Oki Makamura (of NEOMAP project)
Pitt-Rivers lab Christmas lunch (1998?), from L: Lila Janik, ?, Martin Jones, Chris Stevems, LEO HOSOYA, Marco Madella,, Hanna Zawadzka, Victor Paz, Dorian Fuller

Pitt RIver laboratory photos ca 1998. Leo Hosoya, seated at right

(Photo courtesy of Tania Valamoti: see appended comment below)


Thursday, 16 May 2019

Thai rice archaeobotanical study win Ben Cullen prize

A recent paper from the UCL Early Rice project has received the  BenCullen prize from Antiquity for 2019 (jointly with other excellent papers). The paper, “Social responses to climate change in Iron Age north-east Thailand: new archaeobotanical evidence” publishe last year, by a co-authorship team lead by Cristina Castillo (UCL), together with Katie Miller (MSc Environmental Archaeology, UCL, 2014), as well as colleagues from Oxford, Charles Higham from New Zealand and Nigel Chang (Australia) has shared this prestigious prize.

The study is based on a long a long regional sequence of archaeobotanical data in northeast Thailand between 3100 BP and 1300 BP from archaeobotanical analyses at Ban Non Wot and Non Ban Jak, both near modern Phimai. In this sequence dry rice weeds decline as wet rice weeds appear around 2100 BP, with an increase in the wet rice and disappearance of dry rice weeds by 1500 BP. This indicates that in the face of increasing aridity rice cultivation was bolstered by irrigation, but it also suggests that increasingly hierarchical societies in the region were investing increasing labour in more intensive, wet rice production. This indicates that wet rice cultivation in the Southeast was a secondary development driven by growth of social complexity, and perhaps population growth, rather than driving the demographic underpinnings of the initial Neolithic in the region. It can also be seen that in this region climatic conditions that made it harder to grow rice based on rainfall lead to cultural techniques that altered the environment to make this crop possible. While rainfed rice has persisted in the hills of Southeast Asia into recent times, throughout most of the plains wet rice cultivation has been the predominant cultivation system which has supported historically known states and urban systems in the region (as aptly described for the past millennium in James Scott's Art of Not Being Governed). The beginnings of these dynamic between wet rice states and hill tribes could have only started form the Iron Age onwards. 

Friday, 21 September 2018

Pearl Millet genomics and domestication centre

Modern genomes have the potential to reveal alot about evolutionary history and past geography of a crop. Of course there are some limitation to the degree that it hard to account for extirpated past populations, such as the wild rice that used to grow in central China or the wild pearl millet that used to grow what is now the Sahara. A new study of pearl millet (Pennisetum glaucum) by Bugarella et al (2018) provides a convincing set of deductions from genetic history that infer an origin of the crop in the western Sahel/Sahara around what is today northern Mali/northeast Mauretania (map at left), followed by early differentiation between those of the far west (Mauretania/Senegal), and the eastern Sahel (e.g. Sudan) from those in the core zones of western Africa. Based on spatial simulations that take into account a few archaeological data points they also estimated the onset of the expansion of pearl millet as crop out of its centre of origin a starting ca. 4800-4900 years ago. This fits nicely with current archaeobotany. The earliest, already domesticated, pearl millet is from northeastern Mali in the lower Tilemsi valley between 2500 and 2000 BC. Perhaps a parallel trajectory of dispersal is represented by the Tichitt Tradition of Mauretania (from ca. 1700 BC). What remains an open question is whether these two area represent distinct domestication trajectories (a point suggested by MacDonald et al 2009; Manning and Fuller 2014), much as we see the West Asian Fertile Crescent as a mosaic of domesticators across the region as more or less the same time ( or there ). The zone delimited by the genetic study could well represent a sort of "West African Fertile Crescent" in which more than cultural groups were in the process of cultivating and domesticating pearl millet during the middle Holocene. The differentiation of a far western genetic groups would then represent dispersal first through the Tichitt-Oualata traditions of Mauretania and onwards to the Sengal valley- which fits with Brunken, De Wet and Harlan's old taxonomic differentiation of a western race leonis (Economic Botany 1977). A rapid and early spread easterns to the eastern Sahel, which was followed by local introgression with local wild populations, is also implied in this genetic analysis, and fits with the albeit limited archaeobotanical evidence for pearl millet (both morphologically domesticated and wild) alongside cultivated sorghum in the Kasala region of eastern Sudan around 1850 BC, just recently published by Beldados et al. (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?

Improved methods for looking at plant remains in pots

I have previously highlighted the potential of ct-Scanning and synchrotron imaging to look inside archaeological seeds, or seeds inside archaeological pots. And wanted here to highlight the publication of a more detailed protocol for ct-scanning bits of pottery for looking at inclusions, recently published by Barron and Denham in Journal of Archaeological Science: Reports. We have, of course, been looking at impression of plant temper on the surface of sherds from a long time, since the days of Hans Helbaek in the 1940s. It seems unlikely that the utility of casting  and studying impressions on sherd surfaces will go away, as it remains something that is easily carried out in bulk across large sherd assemblage with relative speed and low cost-- providing among other things our best current evidence on sorghum domestication. Nevertheless, the beauty of ct-scanning lies in the ability to see a much larger sample of impressions below the surface, including those that are potentially much better and more completely preserved than those just on the surface. The example of the rice spikelet pictured at left from a sherd from Loc Giang, a Neolithic site in Vietnam is a nice case in point. 

The spikelet bases from this site and sherds from nearby An Son leave no doubt as the domesticated status of rice in this part of Second Millennium BC Vietnam. Interestingly, imaging also found a wild Lemna (duckweed) seed in a sherd from An Son. What remains an open question, however, from a single specimen like this is whether this should be interpreted as a weed of wet rice, or merely a component of clay gathered from a wetland. The weight of archaeobotanical evidence at present points to Neolithic rice in Southeast Asia being large rainfed (see published discussion in "Pathways of Rice Diversification..."), which would not create conditions suitable for Lemna, so I would favour seeing this as a component of the clay. Also of note is the identification of pebble inclusions in sherds from the hunter-gatherers site Con Co Ngua-- such pebbles are the kind of inclusions that have from time to time been mistaken for seeds in pottery...

Tuesday, 3 July 2018

In Memoriam, Gordon Hillman (1943-2018)

It’s with great sadness we bring you the news that Gordon Hillman died on Sunday 1st July. He is survived by his daughter Thilaka, and three Grandsons. Gordon Hillman was a pivotal figure in the development of archaeobotany at the Institute of Archaeology, and through his research, publication and teaching he had a major influence on the direction of the field worldwide, especially with regards to the origins of plant domestication in the Near East and late hunter-gatherer economies.

Gordon Hillman joined the Institute of Archaeology as a research associate in 1981 funded by the UK Science and Engineering Research Council and then became a full-time lecturer in a new archaeobotany post from 1983. David Harris was then Professor of Human Environment, and together they launched a MSc in Bioarchaeology at that time which offered intensive practical training in archaeobotany in alternate years. A generation of professional archaeobotanists, both in commercial archaeology and international academic posts, began their careers through this degree. This degree laid the foundations for the current MSc in Environmental Archaeology.

Gordon Hillman carrying out experimental paddle
 harvesting of wild einkorn wheat in Wales, ca. 1980

Gordon's ground-breaking career in Archaeobotany began in 1969, with a year of training in Mainz, Germany with Dr. Maria Hopf, who at that time was studying plant remains from Jericho. Gordon subsequently, and for nearly five years lived in Turkey carrying out ethnobotanical research, building up a seed reference collection and carrying out flotation at various excavations of the British Institute of Archaeology in Ankara, such as at the sites of Can Hassan III and Asvan. This period was critical in Gordon’s pioneering of a ethnoarchaeological approach to archaeobotanical assemblage formation through the study of traditional crop-processing. It was also the period when much of the core seed reference collection was put together for both the BIAA and the Institute of Archaeology. It was also in this period that he came to the attention of Andrew Moore who was embarking on rescue excavations in northern Syria at Tell Abu Hureyra, which was to prove a seminal research project for Gordon, providing insights into broad spectrum wild plant use in the Late Pleistocene, plausible evidence for early pre-domestication cultivation and the nature of early integrated agro-pastoral economies.
George Willcox and Gordon Hillman examining fieldweeds near Asvan in central Turkey, ca. 1977

Gordon Hillman retired from UCL as Reader in Archaeobotany in 1998, but continued his research, especially on potential wild plants collected and processed by hunter-gatherers, as an Honorary Visiting Professor at UCL. Part of this work inspired the BBC program Wild Foods in which he appeared alongside Ray Mears, gathering and processing various plant foods in Britain, in France, and in Australia with aborigines. The program also produced a colourful book Wild Foods (2007). Gordon continued to work on a comprehensive compilation of wild plant foods of Britain up until his death. As this monumental research effort, drawing on a lifetime of teaching, research, and experimentation, remains a work in progress, an effort is being made to bring out his observations on a plant-by-plant basis on the Wild Plant Foods of Britain blog. For a list of Gordon's many publications (upto 2008), see here. A volume of studies in honour of Gordon Hillman was published in 2009

Gordon photographing flowers during the IWGP
excursion near Girona, Spain (2004)

Gordon was an inspiration to his students, his colleagues, and well beyond through his publications and TV appearances. He was always a thoughtful, provocative and supportive senior colleague that will be dearly missed. I always had much learn at his feet.

Several excellent obituaries have been published in major newspapers and journals, including The Guardian,
The Telegraph,
The Times, and Nature PlantsThe University of Reading has a more Reading-focused account.

Do please add you memories and comments on Gordon Hillman as comments to this blog.

Gordon Hillman, Mary Anne Murray, David Harris, and Sue Colledge,
 in office 311, UCL Institute of Archaeology 1998/99

Ehud Weiss, Ramon Buxo, Ahmed Fahmy and Gordon Hillman, in Girona
during  the 2004 International Work Group for Palaeoethnobotany
Dorian Fuller, Gordon Hillman, George Willcox in Girona at the I.W.G.P. 2004

This photo (below) was found dusty in the back of drawer in the UCL archaeobotany lab. I never got to ask Gordon about it,but I think it is from an early I.W.G.P., in Budapest(?), 1969 or 1971(?). A young Gordon Hillman is in the Middle; also pictured Heather Jarmon (left) and Prof Schulz-Motel (right).

A picnic in Pevensey, Marsh, 2009: Andy Fairbairn, Dorian Fuller, Gordon Hillman, Ehud Weiss
Receiving instruction from Gordon Hillman on the art of acorn processing (June 2010)