Wednesday 22 February 2012

Wild plant use in archaeobotany: a new networking site

A new Groupsite, a kind of private 'facebook' for thematic sharing and networking has been started for the study  the "Ancient Wild Plant Economy", with a group blog and other networking potential. Visit or join at: http://staple.groupsite.com/main/summary.

Something similar, I came across recently in Archaeobotany.net, which provides networking for the archaeobotany of Asia, Australia and Oceania.

Millet ethusiasts and gerbil enthusiats

At first it seems an unlikely place to look for basic information on millets, but it turns out that gerbil enthusiasts also care about millets (e-gerbil). The information is basic, but this website at least includes info on some of the more obscure millets like Browntop millet (Brachiaria ramosa-- they use the Urochloa name); that is more than can be said for wikipedia. They still missed out the Taiwanese oil millet, and some some of the other hypoer-locals, like Digitaria cruciata or the West African fonios. Still, millet enthusiasts are to be encouraged.

Tuesday 21 February 2012

Weeds of Australia database

Just found this. Some basic info on a wide range of "weeds," often with seed images. Includes a bunch of things exotic to Australia that most of us would not regard as weeds, like olives and peaches(!), but it may be a useful resource: http://keyserver.lucidcentral.org/weeds/data/03030800-0b07-490a-8d04-0605030c0f01/media/Html/Index.htm

Friday 17 February 2012

new book: Biodiversity in Agriculture Domestication, Evolution, and Sustainability

Apparently just out from Cambridge University Press. I haven't seen the final form yet, but it contains 8 or 9 archaeological (archaeobotanical, zooarchaeological, ethnobotanical) papers, some modern genetics and  studies of recent agrobiodiversity:  Biodiversity in Agriculture Domestication, Evolution, and Sustainability

Fruitpedia

I just came across the on-line Fruitpedia, a compilation of basic information and photos of edible fruits from all over the world. Looks like a useful resource: http://www.fruitipedia.com/index.htm

Tuesday 14 February 2012

Bay of Bengal ardification data and South Indian agricultural adaptation


A new article, out this week in Geophysical Research Letters, "Holocene aridification of India", by, Ponton, Giosan, an others, presents important new, and quite high resolution, data on past monsoon dynamics and vegetation of peninsular India spanning the whole Holocene. This research, lead by researchers from the Woods Hole Oceanographic Institute, analyzed evidence from a Bay of Bengal sediment core, which captures discharges from the large Godavari river system. The core data comes from carbon isotopes of leaf waxes, reflecting the amount of arid-adapted/ savannah vegetation in the Godavari catchment, and oxygen isotopes from a marine microfossil that record salinity. This points to a general aridification trend over the course of the middle and late Holocene, supporting what we already would infer from pollen data in Rajasthan or monsoon proxies in the Arabian Sea, but this time providing more direct evidence from South India. My own involvement in this work came in the form of trying to think about how this might be correlated with archaeological evidence for settlement, agriculture and population in South India-- where the archaeological record suggests increasing sedentism, population and agriculture in response to, or despite, aridification, a contrast from the Indus region for example where the long-term trend of population depletion as aridification proceeded. This suggests long term cultural adapatation processes to aridification in peninsular Indian agricultural practices.



To quote from part of our conclusion: "The significant aridification recorded after ca. 4,000 years ago may have spurred the widespread adoption of sedentary agriculture in central and south India capable of providing surplus food in a less secure hydroclimate. Archaeological site numbers and the summed probability distributions of calibrated radiocarbon dates from archaeological sites, which serve as proxies of agricultural population, increase markedly after 4,000 BP in peninsular India [discussed in detail in the electronic supplementary text]...In contrast, the same process of drying elicited the opposite response in the already arid northwestern region of the subcontinent along the Indus River. From 3,900 to 3,200 years BP, the urban Harappan civilization entered a phase of protracted collapse. Late Harrapan rural settlements became instead more numerous in the rainier regions at the foothills of the Himalaya and in the Ganges watershed."  Most of the archaeological information is summarized in the electronic supplement, Section 4., and included an attempt to sum Neolithic/Chalcolithihc radiocarbon dates (as limited as they are) and to tally known site numbers through the Iron Age. 

This work complements recent sedimentary studies of the Indus river system, such as the Clift et al Geology paper, blogged earlier.

Saturday 11 February 2012

Expanding Indus fibre crops

Two recent articles in Archaeological and Anthropological Sciences, report new evidence for species used in Harappan fibre work. Rita Wright and colleagues have reported evidence for jute textiles (Cochorus capsularis), based on analysis of fibre impressions preserved in ceramics. As with work done on plant impressions in pottery, this demonstrates that quite fine detail can be preserved in impressions, recorded in casts and studied with SEM. While we have perhaps long suspected jute, which is native to South Asia, was grown in the Indus period, seed finds from sites such as Rojdi (Weber 1991) were ambiguous as whether this species was cultivated, and processed for fibres.  Processing  involves retting (rotting in water), something I encountered a few years ago in the Son valley. My photo below shows a stack of harvested jute which is about to be weighed down with stones (visible in the water behind) for a week or two, before it is pounded to remove the fibres.
Posing for a photo with recently harvested jut that is about to retted  in the side channel of the Son river behind.

 Finds of textiles from eastern Iran published a few years ago by Irene Good, in the book  Ancient Textiles: Production, Craft and Society, included a couple examples of jute, as well as many of sunn hemp (Crotalaria juncea), which were also presumed to have been imported from the Indus to the east. Unfortunately as a small-seeded legume, recognizing the presence of sunn hemp in seed assemblages, especially as this crop and not a related weedy species, is not yet really possible, and could prove intractable. Taken together with evidence for flax seeds, and cotton in the Indus Valley [see my 2008 review pdf], as well as wild silk production (from the Assam silk moth), reported by Good & al. from Harappa in Archaeometry 2009, the Harappan civilization was quite the centre of textile crop diversity in the Bronze Age (compared to apparently only flax cultivation in contemporary Egypt or Mesopotamia). This adds weight to the notion that Indus exports, including those of the textually known Meluhha merchants of the Persian Gulf, included a range of cloth types.


Wild fibre sources were also important, and spun and woven net material from Shahi Tump, has also been reported recently by Thomas, Tengberg et al. in AASc. In this case, they appear to be using the local dwarf Mazari palms (Nannarrhops ritchiana). One of the excellent components of the paper is comparative study of palm phytoliths (admittedly of the limited taxa range that might be found in Pakistan), but which shows clearly that there is significant and taxonomically-informative variation in the spikey silica balls that palms produce. The next challenge will be doing more work on this variation and it taxonomic interpretation in the palm-rich tropics.


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.

Friday 10 February 2012

Archaeobotany of Near Eastern domestication: new special issue


The latest issue of Vegetation History and Archaeobotany (Feb. 2012) is a special issue on Near Eastern origins: From collecting to cultivation:transitions to a production economy in the Near East. Some of my own contributions to this discussion have been blogged previously. But as a whole issue there is a lot of important new data, and discussion herein. Although Current Anthropology has a recent volume on "origins of agriculture: new data, new ideas" I actually think there is a lot more new data, and ideas, in this specialist journal. Of course it is only about the Fertile Crescent, and we need more equivalent work on other world regions.



seeds & chaff from Iran and SE Turkey (Riehl et al)
As for what is in the issue, best to quote from the editorial by Willcox, Nessbit and Bittman: "The selected articles in the current issue throw new light on our understanding of how Homo sapiens became caught in the agriculture trap in the Near East. They are the outcome of the session entitled ‘Origins of agriculture in the Near East’ held at the 15th IWGP conference in Wilhelmshaven 2010. The subject is constantly being revised as new information and more refined analyses become available, so these papers provide a state of the art in 2010/2011. Each major discovery adds complexity to what has become a multi-faceted puzzle with data being drawn from disciplines as wide apart as archaeology and genetics, plant biology and palaeo-climatology. In this issue papers concentrate on results obtained from charred plant remains and their interpretation.".... " with hindsight simple hypotheses are no longer plausible given the archaeological and environmental diversity within the Fertile Crescent. This complex diversity is exemplified by the vast geographical area where transition sites are located, which spans different climate and vegetation zones. Thus, sites in the north of the Fertile Crescent are 1,000 km from those in the south and likewise in the east–west direction. Archaeological diversity is exemplified by the extended chronological range of transition sites. We can trace the use of wild cereals back to about 23,000 years ago when habitations consisted of simple brush huts to villages with sophisticated architecture associated with the earliest domesticated cereals 12,500 years later."


On a personal note, this issue marks a major foray into thinking about the dynamics of domestication is what remains the best archaeobotanically studied region of agricultural origins, but even here we still have a quite patchy dataset to work with.


Here's the contents list.







Wednesday 8 February 2012

The rapid spread & differentiation of maize: new Peruvian data

New finds from the N. Peruvian coast report clear evidence for an earlier arrival of maize the region than previously thought (Grobman & al., PNAS), and with wonderful dessicated preservation indicating that they are popcorn varieties, but flourly varieties are also present. That there is a popcorn indicates quite rapid early varietal diversification, and these show already traits of South American rather Mesoamerican varieties. A direct AMS date puts these back to at least 4500 BC, so still a few millennia after perhaps 7000 BC date for the earliest maize in its Mesoamerican place of origin. The macro-remains are augmented by phytolith analyses and strach grains extracted both from the maize cobs and tools. Of methodological interest is the apparent discrepancy between dates on dessicated and dates on carbonized material, with the dessicated stuff being way to young. This may mean the dried stuff may sometime get contaminated with young carbon in some way (whereas the charred stuff has it true carbon fixed nicely by carbonization). Also of note is that maize is apparently not the most common plant find, and was not the dietary staple, although the present PNAS article focuses on the details of maize and we will have to await another forthcoming publication in Antiqiuty for more on the chillis, beans, squash and wild plants. Another discussion of this paper can be found in ScienceDaily news report from a couple of weeks ago.

Monday 6 February 2012

Pearl millet demographic modelling: 3rd millennium BC and importance of flowering time

A new article in Molecular Biology and Evolution by Clotault et al "Evolutionary History of Pearl Millet (Pennisetum glaucum [L.] R. Br.) and Selection on Flowering Genes since Its Domestication" has some exciting and intriguing results. They have done demographic modelling, using a number of different scenarios of gene flow, based on 20 random genes, and they have also looked for selective sweeps, finding evidence for strong selection on flowering-time related genes. Although they have only modelled single domestication scenarios (which is by no means a done deal in Pearl millet), they have nevertheless taken into explicit account the notion of protracted domestication process (sensu Allaby et al 2008 or Allaby 2010), with gradual fixation of domestication traits, with exponential rather than instantaneous population growth after the bottleneck. 

They find a bottleneck strength and reduction of genetic diversity that fall amongst those estimated for other crops. Their estimated time for domestication returned an intriguingly plausible 4800 years ago, just a few centuries before the earliest archaeological evidence for domestication pearl millet in the Tilemsi valley (see Manning et al, blogged previously). The evidence they have found for selection on flowering related genes makes a whole lot of sense, because the dispersal of pearl millet from a Sahelian zone southwards crossed many different ecological zones, for which adjustments in seasonality would indeed have been important.

Roman bottlegourds from Asia

A new article by Angela Schlumbaum and Patricia Vandorpe in Vegetation History and Archaeobotany provides a review and new data on Roman era bottlegourds in Europe. Despite the fact the bottlegourds originated in eastern Africa (Decker-Walters et al 2004) and most likely were carried to Asia sometime in the Pleistocene (and thence to the Americas-- as discussed in my short contribution on East Asian Neolithic and Jomon gourds in Economic Botany 2010), gourds were only introduced to Europe in the Roman period. New aDNA confirms, at least where DNA markers could be extracted, that these were Asian (rather than African). Seed morphometrics are reported from several modern and archaeological populations, and while the L:W ratio does not clearly demarcate Asian versus African genotypes, it does seem to suggest multiple morphotypes (at least two) in Roman Europe, although both would fit within a broader range of Asian diversity.   

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

Sunday 5 February 2012

Millet starches: towards a systematic and quantitative approach

Yang Xiaoyan et al. have published their latest key to millet starch identification (for China) in J. of Archaeological Science "From the modern to the archaeological: starch grains frommillets and their wild relatives in China". This is an important development, partly because it is the largest comparative study yet from that part of the world (although arguably still not large enough in terms of taxa and populations!), but mainly because it provides some highly plausible and well-quantified guidelines on millet starch identification. It shows quite clearly that there is quite a lot of variation within a grain, a species and genus, the Paniceae, but also degrees of underlying similarity. The take home message is that every individual starch  is unlikely to be identifiable to the same level, to species or genus, but that some may be highly suggestive (the especially large and wrinkled examples are more common in Setaria italica than in wild Setaria or Panicum), and if on an assemblage level morphometric can be used to assess the probability of certain taxa. In other words it is the first step in building a probabilistic, rather than some qualitatively absolute, determination that the Chinese millets or there wild relative were present. Interestingly it indicates that Setaria italica is in principle far more recognizable than Panicum miliaceum, which has more 'generic' millet-grass starch. This means that rather than trying to take a small sample of few starch grains and pronounce a species presence that may not be believable, a more stasticial approach can be taken to determine a degree of likelihood. Such a quantitative apporach also open the possibility of tracking assemblages changes, which in turn might be connected to other lines of evidence for agriculture change or even plausibly put together in models about population change such as domestication processes, since Setaria viridis and Setaria italica differ in their starch grain assemblages. It also raises another potential area of investigation, which require further work, environmental conditions, since there does appear to latitude-related variation amongst  Setaria italica populations studies-- so further work is needed. The this is the best step in the right direction we have seen increasingly popular Chinese starch research world.

Thursday 2 February 2012

What role wild foods for Neolithic farmers? A proposed thematic session for next years IWGP

Next year (2013) sees the next International Workgroup in Palaeoethnobotany conference go to Thessaloniki Greece. Together with the overall conference organizer I am proposing a session on the role of wild foods in the Neolithic and what was special about it. This will be circulated through the regular conference channels, but to start a precis is here.


The role wild foods amongst early farmers and late foragers
(Proposal for a thematic session at IWGP 2013, Greece) By Dorian Q Fuller and Soultania Valamoti

The Neolithic transition to cultivation and reliance on domesticated grains is a major focus of archaeobotanical research, but do we have a “cereal-bias” that means we undervalue the continued roles of wild food sources amongst early farmers? Looking over archaeobotanical reports from Early Neolithic Europe or the Prepottery Near East, one often finds quite substantial quantities of remains of wild food resources, potential co-staples,  or secondary staples, perhaps more than just fall back foods. The recent rise of archaeobotanical sampling in China has revealed that in the same culture in which domestication of rice is taking place the quantities of wild nut remains are vast and out- number rice. These wild foods might include nuts (Corylus or Quercus in Europe, Pistacia or Amygdalus in the Near East, Lithocarpus/Quercus, Trapa, Euryale in East Asia) or nutlets (Polygonaceae, Cyperaceae) or some small seeds (e.g. Chenopodium), as well as wild fruits. While the large quantities of these show some similarities to pre-agricultural assemblages: what has changed in their use with the advent of agriculture? There also appears to be an almost uniform contrast with later prehistory: perhaps sites of the later Neolithic or Bronze Age or Iron Age provide scant evidence for these same taxa, implying some changes since the earlier agricultural economies. Drawing largely on American evidence and Jomon Japan, Bruce Smith (2001), proposed the concept of “low-level food production“ for the first domesticators and early cultivators, in which the majority of food is inferred to come from wild sources, but despite the high levels of wild foods in the earlier Neolithic across Eurasia, it seem difficult to accept that this “low level” category necessarily applies where cereals clearly have high ubiquity and counts. The aim of this session to consider in further detail how particular sites and regional sequences inform on the role and importance of wild foods in the early Neolithic and how this may have differed from either full foraging “broad spectrum” economies or later more intensively agricultural economies. Is there a wild-side to the Neolithic that made it different from later agricultural economies? And how do we accommodate this to our understanding of the beginnings and spread of agriculture?

Paper presentations and poster presentations welcome. Please indicate your interest by emailing a provisional title to Dorian (d.fuller@ucl.ac.uk) , but also return your pre-registration form to Tania Valamoti.