Category Archives: diet

A way to settle when the domestication of cattle/cereals occurred?

Reconstruction of African human diet using bone collagen carbon and nitrogen isotope ratios

Behavioural modifications associated with the exploitation of new food resources have been linked to major steps in hominid evolution and in subsequent human cultural development1,2. Testing of specific hypotheses concerning the influence of dietary change on these processes would be facilitated by quantitative estimates of early hominid and human diets. Although most methods of obtaining such evidence provide only qualitative information2, the stable carbon and nitrogen isotope ratios of animal tissues, and in particular, bone collagen, can be used to quantify the consumption of foods having different isotopic compositions3−5. As reported here, analysis of the collagen of historic and prehistoric African human populations from Kenya, Tanzania and South Africa that have reasonably well-known diets shows that stable carbon and nitrogen isotope ratios in bone collagen can distinguish marine foragers from populations consuming terrestrial resources, pastoralists from farmers, farmers consuming grains from those consuming non-grain crops, and camel pastoralists from capri-bovine pastoralists.

I was looking around to see if isotopes could tell whether people were consuming dairy products in their diets. This seems promising. I know it’s been used on Mesolithic Europeans like Trent Woman, I wonder if anyone has ever thought to try it on the Nabta Playa human remains? Or the remains in early Neolithic Turkey to get at the dates grains and dairy started to be consumed. Just a thought. Maybe I should email it to Fred Wendorf.

Baka Pygmy management of wild yams

THE MANAGEMENT OF WILD YAM TUBERS BY THE BAKA PYGMIES IN SOUTHERN CAMEROON

 Wild yams (Dioscorea spp.) are primordial sources of carbohydrates for many hunter-gatherers of African forests. Yams play a key role in the symbolic perception of the forest by the Baka Pygmies of Southern Cameroon. The Baka have elaborated an original form of wild yam exploitation that I have termed “paracultivation”. Paracultivation defines a set of technical, social and cultural practices aiming at managing wild resources while keeping them in their natural environment.

 In 1994, I undertook an experimental survey to estimate the effect of paracultivation on survivol and growth of yam plants. Preliminary results presented here demonstrate that paracultivation increases the production of tubers without affecting plant survivorship. Furthermore, it allows a better control of the spatial and temporal availability of yam resources by the Baka.

This study has opened up new perspectives on the evolutionary ecology of tuber producing tropical forest plants. Paracultivation encourages us to reconsider the interactive process between forest dwellers and their environment.

I’m having a domestication research moment today, after reading an interview full of inaccuracies by a renowned professor (I won’t name names). After spotting two major screw ups in his logic and several outright wrong ‘facts’, I’ve decided to be more thorough and start digging into West African yam domestication and the process that leads to it. I’ve blogged one paper that describes how wild yams are transplanted nearer to home by hunter gatherers, and this paper, gives a nice description of how the wild yam resource is managed by hunter gatherers. The author describes it as ‘paracultivation’, where wild plants are replanted after harvesting tubers, or moved closer to the home of the hunter gatherers. It’s a step on the route to domestication, and does show hunter gatherer behaviour regarding plants to be a lot more complex than most people think.

The ‘almost’ domestication of Barbary sheep at Uan Afada

A Barbary sheep.

Taming Barbary sheep: wild animal management by Early Holocene hunter-gatherers at Uan Afuda

Yet another Pdf involving the Libyan Sahara.

The main observation of this paper is the thick layers of Barbary sheep dung at the Uan Afada site. Since Barbary sheep were never actually domesticated, this seems to describe an intermediate stage seen in modern hunter gatherers where wild livestock is kept and fattened up, sometimes to provide a reliable source of meat for special occasions. It’s an intermediate and necessary step to domestication, but fully domesticated sheep and goats arriving from the near East in the neolithic probably interrupted the domestication process. As the paper says:

Management of animals does not  mean domestication, also in our view, but rational control of animal resources, which may not produce any morphologically domesticated animals. Such behaviour is not rare in the ethnographic record: we can recall activities of driving and containing animals such as bison, deer and antelope in North America (Chang and Koster 1986); the interaction between reindeer and humans in North Europe (Ingold 1980), and other operations in which wild animals are used by human groups to perform specialised activities like hunting.

Which is what I suspect was happening with the cattle in Nabta Playa too.

The Tadrart Acacus mountain range.

tadrart

On a similar line;  New investigations in the Tadrart Acacus, Libyan Sahara, another pdf.

And this paper.

 Dismantling Dung: Delayed Use of Food Resources among Early Holocene Foragers of the Libyan Sahara

At Uan Afuda, and other Early Holocene sites of the Acacus mountains, in the Libyan Sahara, dung layers and plant accumulation are a major, but repeatedly neglected, feature of hunter-gatherer communities. To understand the formation and meaning of such features, a multidimensional analysis has been undertaken, combining micromorphological, palynological, botanical, archaeozoological, and archaeological data. The hypothesis here formulated is twofold: plant accumulations are evidence of anthropic activity aimed at the storage of fodder; and dung layers are related to a forced penning of a ruminant, very likely Barbary sheep (Ammotragus lervia). The exploration of these two features has hinted at the existence of a deep reciprocal relationship, which has been interpreted as the cultural control of wild Barbary sheep, leading to a delayed use of food resources. This behavior may be considered an opportunistic strategy adopted to minimize the effects of lean periods and implicates increasing cultural complexity within Late Acacus Saharan forager societies of the 9th millennium B.P.

Domestication rates in cereal and pulse crops

Contrasting Patterns in Crop Domestication and Domestication Rates: Recent Archaeobotanical Insights from the Old World
Dorian Q Fuller*
Institute of Archaeology, University College London, 31–34 Gordon Square, London WC1H 0PY, UK

Received: 20 September 2006   
   Background: Archaeobotany, the study of plant remains from sites of ancient human activity, provides data for studying the initial evolution of domesticated plants. An important background to this is defining the domestication syndrome, those traits by which domesticated plants differ from wild relatives. These traits include features that have been selected under the conditions of cultivation. From archaeological remains the easiest traits to study are seed size and in cereal crops the loss of natural seed dispersal.

Scope: The rate at which these features evolved and the ordering in which they evolved can now be documented for a few crops of Asia and Africa. This paper explores this in einkorn wheat (Triticum monococcum) and barley (Hordeum vulgare) from the Near East, rice (Oryza sativa) from China, mung (Vigna radiata) and urd (Vigna mungo) beans from India, and pearl millet (Pennisetum glaucum) from west Africa. Brief reference is made to similar data on lentils (Lens culinaris), peas (Pisum sativum), soybean (Glycine max) and adzuki bean (Vigna angularis). Available quantitative data from archaeological finds are compiled to explore changes with domestication. The disjunction in cereals between seed size increase and dispersal is explored, and rates at which these features evolved are estimated from archaeobotanical data. Contrasts between crops, especially between cereals and pulses, are examined.

Conclusions: These data suggest that in domesticated grasses, changes in grain size and shape evolved prior to non-shattering ears or panicles. Initial grain size increases may have evolved during the first centuries of cultivation, within perhaps 500–1000 years. Non-shattering infructescences were much slower, becoming fixed about 1000–2000 years later. This suggests a need to reconsider the role of sickle harvesting in domestication. Pulses, by contrast, do not show evidence for seed size increase in relation to the earliest cultivation, and seed size increase may be delayed by 2000–4000 years. This implies that conditions that were sufficient to select for larger seed size in Poaceae were not sufficient in Fabaceae. It is proposed that animal-drawn ploughs (or ards) provided the selection pressure for larger seeds in legumes. This implies different thresholds of selective pressure, for example in relation to differing seed ontogenetics and underlying genetic architecture in these families. Pearl millet (Pennisetum glaucum) may show some similarities to the pulses in terms of a lag-time before truly larger-grained forms evolved.

As I recall, the lentils at Franchthi cave were just slightly bigger than wild lentils, suggesting that the 13,500 date for domestication could be push back possibly as much as 17,000 BP ( I’d say 15,000 BP was more likely). I’d seriously recommend reading this whole paper through if you are interested in the process of domestication of crops. It includes some Indian beans, rice, as well as African pearl millet, and is about the most comprehensive paper I’ve seen on the subject.

It also names the South Asian location of rice domestication as the middle of the Ganges valley, and has some very useful graphs showing the levels of domestication in various near Eastern sites. It suggests that an increase in seed size in cereals is evident for quite some time before a non shattering rachis is selected in. One interesting fact didn’t know was that millet was much more widely grown in China about 8,000 years ago than rice. One to read a couple of times through.

FIG. 1. An evolutionary model from foraging to agriculture, with archaeobotanical expectations indicated at the bottom (modified from Harris, 1989). The stages of pre-domestication cultivation are shaded. In this version, domestication is represented as a process of gradual frequency change, with an earlier, more rapid ‘semi-domestication’ and a later, slower fixation of full domestication. The gap in time elapsed between these two can be taken as a minimal estimate of domestication rate (d.r.).

FIG. 2. Map of south-west Asia, showing the locations of sites with archaeobotanical evidence that contributes to understanding the origins and spread of agriculture. Sites are differentiated on the basis of whether they provide evidence for pre-domestication cultivation, enlarged grains, mixed or predominantly domestic-type rachis data. Note that these sites represent a range of periods, and many sites have multiple phases of use, in which case the earliest phase with significant archaeobotanical data is represented. Shaded areas indicate the general distribution of wild progenitors (based on Zohary and Hopf, 2000, with some refinements from Willcox, 2005). It should be noted that wild emmer (Triticum dicoccoides) occurs over a sub-set of the wild barley zone, and mainly in the western part of the crescent.
Archaeological evidence indicates that the entire domestication syndrome did not suddenly appear when people began to cultivate plants. Rather, different aspects of the syndrome evolved in response to the new ecological conditions of early cultivation. What these data suggest is that in domesticated grasses, changes in grain size and shape (‘semi-domestication’) evolved prior to non-shattering ears or panicles (‘domestication’ sensu stricto). While initial grain size increases may have evolved during the first centuries of cultivation, within perhaps 500–1000 years, non-shattering was much slower, becoming fixed about 1000–2000 years subsequently. Pulses by contrast do not show evidence for seed size increase in relation to the earliest cultivation, but seed size increase may be delayed by 2000–4000 years. This implies that conditions that were sufficient to select for larger seed-size in Poaceae were not sufficient in Fabaceae. This implies different thresholds of selective pressure in relation to differing seed ontogenetics and underlying genetic architecture in these families. Pearl millet (Pennisetum glaucum) may show some similarities to the pulses in terms of a lag-time before truly larger-grained forms evolved. These results may aid in predicting when and where certain crop domestications are likely to have occurred based on counting backwards from the earliest known domestic finds. Thus, for example, we would predict that pearl millet cultivation began by 3200–2700 BC. These results also raise questions about taxonomically linked differences in evolution under the selection forces of cultivation.

Reconsidering sickles and cereal domestication
There has been a tendency to assume that harvesting with a sickle was the selective force that led to domestication, i.e. non-shattering (as discussed above). The archaeological evidence, however, does not support this in any documented case. In China, as discussed already, rice grains begin to plump and increase in size but domestication is indicated by the shift towards predominantly mature-grained harvests (and inferred non-shattering), during the fifth millennium BC, and by approx. 4000 BC. In this region there are no clear archaeological sickles until after 3500 BC, the Later Songze period (approx. 3500 BC), after which they become widespread in the Liangzhu culture (3300–2200 BC). These sickles may be a cultural borrowing from millet cultivators in central China, where such tools were in use since at least 5000 BC (cf. Chang, 1986). Even in central and northern China, the earliest sickles occur at sites that already have millet cultivation, and earliest documented domestic millets from Xinglonggou (near Chifeng, China), before 6000 BC (Zhao, 2005), come from a culture without sickles. In China, sickles consistently represent a technology development after domesticated plants are fully established.

In the Near East sickles were in use prior to agriculture and must now be argued to be transferred to agriculture relatively late, after domestication. Preserved sickles, and more commonly lithic sickle blades, are known from Natufian contexts (13 000–10 500 BC), in a period for which there is no evidence for domesticates, and non-shattering domesticates continued to be absent through the PPNA (through 8800 BC) (see Fig. 3). Microscopic studies of ‘sickle gloss’ have been used to suggest they were cereal-harvesting (Unger-Hamilton, 1989; Anderson, 1992), but we cannot rule out harvesting of sedges (Cyperaceae) and reeds (Phragmites) as materials for basketry or thatching. As suggested by Sauer (1958), the early Natufian sickles were prototype saws, designed for raw material gathering rather than seed collecting. As indicated by the archaeobotanical evidence reviewed above, the rate of evolution of tough rachis einkorn and barley is far too slow to be accounted for by a model of strong selective pressure that would be expected if sickling was carried out regularly, as modelled by Hillman and Davies (1990). Thus, it would appear that early cultivators continued to employ the time-efficient harvesting methods associated with hunter-gatherers. Once cultivated, and populations had noticeably large proportions (majorities) of non-shattering types, then the transfer of the sickle technology to agriculture may have been seen as an obvious enhancement. In evolutionary terms the sickle is thus an ‘exaptation’ (sensu Gould and Vrba, 1982), in that it developed for some other purpose, and was later transferred to crop-harvesting of already domesticated crops.

I would propose alternative explanations for the selection of domesticated-type crops that can account for the slow creep towards domestication. As others have noted, the harvesting of cereals when green, i.e. immature, regardless of technique, will not select for domesticated types (Hillman and Davies, 1990; Willcox, 1999). Harvesting green, however, may not provide full returns from a given stand of crops, as additional seeds (including late tillers) may form and approach maturation subsequent to the harvest. For the early farmers, who have invested significant labour into a restricted unit of land, it becomes important to maximize returns from that unit of land (as noted by Hillman and Davies, 1990: 69; Bar-Yosef, 1998). This may encourage multiple episodes of harvest. Later harvestings, whether by plucking or beating, will encounter domesticated genotypes in a higher frequency than earlier harvests. If, as an aspect of random variation, some farming households choose to store the late harvest as seed for sowing the following year, those fields so sown will start an increase in the domesticated type. Other households, however, may store for sowing their earlier harvests. Therefore, taken at the level of a human community, or on a regional scale, there might be only a very small proportion of sown crop that had some selection for the domesticated type. Such a model might therefore account for significantly longer periods involved in the fixation of non-shattering types in cultivated populations. By contrast, every farmer and every sown population would be under selective pressure to germinate rapidly, leading to seed size increase and loss of germination inhibitors. Similarly, natural selection for dispersal aids such as awns will be uniformly reduced. Thus, we should expect these ‘semi-domestication’ traits to evolve more rapidly.

Domestication as an interdisciplinary study of evolution
Domestication in plants is not one thing, nor has it been one uniform process. While there are recurrent parallels, due to the same selective pressures of cultivation, different domestication traits have evolved at different rates and these have varied markedly across families, such as between cereals and legumes. Further archaeobotanical research will help to pin down the actual rates at which different domesticates evolved, and needs to be expanded to address a larger range of species. The archaeological record also provides insights into what people are doing during this evolutionary process in terms of their technologies and ecological adaptations. Understanding past domestications is an exciting area of interdisciplinary investigation, between archaeologists and plant scientists, which may offer insights relevant to future directions in the evolution of crops under human manipulation.

Did nutrition cause the Flynn effect on IQ?

What has caused the Flynn effect? Secular increases in the Development Quotients of infants

Richard Lynn

aUniversity of Ulster, Coleraine, Northern Ireland, BT52 1SA, UK

Received 23 March 2008;  revised 17 July 2008;  accepted 17 July 2008.  Available online 21 September 2008.
Abstract
Results of five studies show that during the second half of the twentieth century there were increases in the Development Quotients (DQs) of infants in the first two years of life. These gains were obtained for the Bayley Scales in the United States and Australia, and for the Griffiths Test in Britain. The average of 19 data points is a DQ gain of approximately 3.7 DQ points per decade. Similar gains of approximately 3.9 IQ points per decade have been present among pre-school children aged 4–6 years. These gains are about the same as the IQ gains of school age students and adults on the Wechsler and Binet tests. This suggests that the same factor has been responsible for all these secular gains. This rules out improvements in education, greater test sophistication, etc. and most of the other factors that have been proposed to explain the Flynn effect. It is proposed that the most probable factor has been improvements in pre-natal and early post-natal nutrition

More from professor Lynn; a bit of an ass at times, but not stupid. This suggests that most of the IQ gains made through the 20th century a mainly attributable to better nutrition (we are about 30 points smarter than we used to be in the Victorian era).

This would also be another kick in the teeth for the ‘environment only’ supporters who believe we are all born the same, but our IQ’s vary solely from environmental factors. Generally malnutrition isn’t common even among the poorest groups in the West, so this makes most IQ differences you see between individuals due to genetics. The current estimate of heritability is 70% ish, with most of the 30% being nutrition and infantile stimulation. I’d like to see a study of vegetarian/vegan children to see if they compare well to omnivores.

Oldest agriculture in Northern Atlantic Spain.

The oldest agriculture in northern Atlantic Spain: new evidence from El Mirón Cave (Ramales de la Victoria, Cantabria)

Leonor Peña-Chocarroa, Lydia Zapatab, Maria Jose Iriarteb, Manuel González Moralesc and Lawrence Guy Strausd, ,

aLaboratorio de Arqueobotánica, Instituto de Historia, CSIC, C/ Duque de Medinaceli 6, 28014 Madrid, Spain bArea de Prehistoria, Universidad del Pais Vasco, 01006 Vitoria-Gasteiz, Spain cInstituto de Prehistoria, Universidad de Cantabria, Avda. de los Castros, 39005 Santander, Spain dDepartment of Anthropology, University of New Mexico, Albuquerque, NM 87131, USA

Received 2 November 2004;  revised 2 December 2004.  Available online 16 February 2005.

Abstract
Emmer wheat (Triticum diccocum) has been positively identified from the stratigraphically oldest ceramic- and domesticated livestock-bearing level of El Mirón Cave in the Cantabrian Cordillera. The grain is AMS 14C-dated to 5550±40 BP. This date is congruent with six others from the same layer, higher within which were found other grains of wheat, including einkorn as well as emmer. Although wild ungulates (mainly red deer) were still hunted, abundant ovicaprines, together with small numbers of cattle and pigs, appear in this level-for the first time in the 40,000-year record at El Mirón. Potsherds (undecorated, but of very good quality) also appear abruptly and abundantly. However, the associated lithic assemblage contains specific tool types also found in late Mesolithic contexts in Cantabrian Spain. In addition to the full suite of Neolithic indicators at El Mirón, as confirmed by less unambiguous early agro-pastoral evidence from other sites in the Vasco-Cantabrian region, there are megalithic monuments both in the vicinity of the cave and throughout the region that are similarly dated. All these data tend to suggest that Neolithic adaptations—already present about a millennium earlier not only along the Mediterranean coast, but also much closer, to the southeast of the Cordillera—were quickly adopted as “a package” by Cantabrian Mesolithic foragers, possibly as a consequence of social contacts with Neolithic groups in southern France and/or the upper Ebro basin of north-central Spain.

Stone-age pilgrims ‘held barbecues at Stonehenge’

Stone-age visitors to the site of Britain’s most famous historical monument held “bring your own barbecues”, new research has revealed.
 
By Richard Gray, Science Correspondent
10 Sep 2008

Cattle were brought to Stonehenge from as far as Wales and even the Scottish Highlands Photo: Analysis of animal remains found near to Stonehenge has shown that cattle were brought to the area from as far away as Wales or even the Scottish Highlands.

Scientists tested the chemical fingerprint of cattle teeth found at Durrington Walls, a Neolithic monument built 500 years before Stonehenge.

They found that far from being local, the animals could only have been reared in areas of Wales or Scotland, which have high levels of the chemical element strontium in the soil.

It suggests that the area around Stonehenge was already an important national site long before the famous stone circle was erected and attracted pilgrims from all over the British Isles.

Dr Jane Evans, from the British Geological Survey who carried out the research, said: “It looks like people were driving cattle to the area from a significant distance away.

“The area must have been an important place for rituals and gatherings long before the first stones were laid at Stonehenge itself.

“People are coming from considerable distances and dispersion in order to have feasts and were bringing their own food supplies for what must have been a kind of bring your own beef barbecue.”

Durrington Walls 500 metre wide circular earthwork that was studded with wooden posts and dates back to more than 3,000BC.

Stonehenge was not built until around 2,500 BC.

Large numbers of animal remains have been found at the site suggesting it was a hotspot for feasts.

Speaking at the British Association for the Advancement of Science, Dr Evans explained they used teeth to examine where the cattle had come from because they absorbed strontium from soil through the grass they ate in the same way as teeth absorb calcium from food.

Different types of strontium, known as isotopes, are found in different geological areas of the country.

The nearest match to those found at the Durrington site were extremely old rocks found in Wales and the Highlands.

Saw it on Dienekes blog, which I shamelessly mine for info once a month.