Dietary variability of early farmers from Southeastern Italy

Am J Phys Anthropol DOI: 10.1002/ajpa.22134

Examining dietary variability of the earliest farmers of South-Eastern Italy

Roberta Lelli et al.

Stable isotope analysis of human remains has been used to address long-standing debates regarding the speed and degree to which the introduction of farming transformed diet. In Europe, this debate has centered on northern and Atlantic regions with much less attention devoted to the arrival of farming across the Mediterranean. This study presents carbon and nitrogen stable isotope analyses of collagen from 19 human and 37 faunal remains from eight sites in the Apulia and Marche regions of south-eastern and central Italy, dating to the early phases of agricultural adoption during the first half of the 6th Millennium BC. Where collagen preservation permitted, sulfur stable isotope analysis was also performed. Overall, there was significant isotopic variation between the different geographic regions, although there was also considerable uncertainty in interpreting these data, especially given heterogeneous isotope values for fauna from site to site. By considering isotope data from each region separately, it was noticeable that the degree of carbon isotope enrichment in humans compared to fauna was higher for individuals buried near the coast, consistent with increased marine consumption. Coastal individuals also had higher sulfur isotope values. Nitrogen isotope values were very variable between individuals and regions and, in some cases, were consistent with very high plant food consumption. Overall, early “farmers” in south-east and central Italy consumed a wide range of foods, including marine, and had much more variable stable isotope values than those observed in central and northern Europe during this period, perhaps indicating a different mode for agricultural adoption.

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Soil and climate as economic destiny

Figure 1 (on the left) Modelled “suitability” (probability of occurrence, Maxent) for (A) agriculture, (B) sedentary animal husbandry, (C) nomadic pastoralism, and (D) hunting and gathering.

From the paper:

Our simplistic exercise showed that a “geo-deterministic” approach can predict surprisingly many features of human cultural geography without any explicit cultural or historical assumptions. Although many deviations require further factors for a satisfying explanation, the nature of these deviations invite the generation of hypotheses for further research. Our ‘null model’ offers a highly parsimonious, empirically supported explanation to the question of why some regions are more “powerful” than others, supplementing the idea of a historical effect operating through the timing of transition to agriculture [2].

In some instances, our model may actually provide a simpler explanation. Putterman [10], for example, suggested that the dominance of Western European cultures indicates the transmission of “civilization” traits (other than knowledge on agriculture) from regions of first domestication. Our data indicate that higher climatic suitability may have been sufficient for Europe to “catch up”, allowing for much higher population densities than, e.g., the “fertile crescent” region. Models of “suitability” under past climatic scenarios may be helpful to evaluate this. Similarly, models applied to predicted future climatic scenarios may be useful to anticipate changes of the economic suitability of landuse types.

However, our model has clear deviations in some regions that may well be explicable by the availability of animals and plants suitable for domestication (e.g., central Africa). Apart from that, and more importantly, we know that human societies and economies went through historical development, so ignoring history may not always be the best strategy to understand causalities. This problem occurs also with other research questions in biogeography, e.g. when investigating global biodiversity patterns [45]–[47]. Nevertheless, our ‘null model’ will be a useful tool in identifying regions that require further investigation to understand additional processes that shape the distribution and performance of human economic traits.

I really like this type of paper that looks at a simple explanation for a phenomenon, in this case, economic output as a product of soil/climate quality and suitability. As the authors point out, their "null" model has its limitations, and it is precisely in regions of the world where its predictions do not match the observations, that we should look for additional factors (besides soil and climate) to explain economic traits.

Related: Soil and Greek temples.

PLoS ONE 5(5): e10416. doi:10.1371/journal.pone.0010416

Is the Spatial Distribution of Mankind's Most Basic Economic Traits Determined by Climate and Soil Alone?

Jan Beck, Andrea Sieber

Abstract

Background
Several authors, most prominently Jared Diamond (1997, Guns, Germs and Steel), have investigated biogeographic determinants of human history and civilization. The timing of the transition to an agricultural lifestyle, associated with steep population growth and consequent societal change, has been suggested to be affected by the availability of suitable organisms for domestication. These factors were shown to quantitatively explain some of the current global inequalities of economy and political power. Here, we advance this approach one step further by looking at climate and soil as sole determining factors.

Methodology/Principal Findings
As a simplistic ‘null model’, we assume that only climate and soil conditions affect the suitability of four basic landuse types – agriculture, sedentary animal husbandry, nomadic pastoralism and hunting-and-gathering. Using ecological niche modelling (ENM), we derive spatial predictions of the suitability for these four landuse traits and apply these to the Old World and Australia. We explore two aspects of the properties of these predictions, conflict potential and population density. In a calculation of overlap of landuse suitability, we map regions of potential conflict between landuse types. Results are congruent with a number of real, present or historical, regions of conflict between ethnic groups associated with different landuse traditions. Furthermore, we found that our model of agricultural suitability explains a considerable portion of population density variability. We mapped residuals from this correlation, finding geographically highly structured deviations that invite further investigation. We also found that ENM of agricultural suitability correlates with a metric of local wealth generation (Gross Domestic Product, Purchasing Power Parity).

Conclusions/Significance
From simplified assumptions on the links between climate, soil and landuse we are able to provide good predictions on complex features of human geography. The spatial distribution of deviations from ENM predictions identifies those regions requiring further investigation of potential explanations. Our findings and methodological approaches may be of applied interest, e.g., in the context of climate change.

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Reduced Y chromosome diversity of Central Asian pastoral populations

Curr Biol. 2007 Jan 9;17(1):43-8.

From social to genetic structures in central Asia.

Chaix R. et al.

Pastoral and farmer populations, who have coexisted in Central Asia since the fourth millennium B.C. , present not only different lifestyles and means of subsistence but also various types of social organization. Pastoral populations are organized into so-called descent groups (tribes, clans, and lineages) and practice exogamous marriages (a man chooses a bride in a different lineage or clan). In Central Asia, these descent groups are patrilineal: The children are systematically affiliated with the descent groups of the father. By contrast, farmer populations are organized into families (extended or nuclear) and often establish endogamous marriages with cousins . This study aims at better understanding the impact of these differences in lifestyle and social organization on the shaping of genetic diversity. We show that pastoral populations exhibit a substantial loss of Y chromosome diversity in comparison to farmers but that no such a difference is observed at the mitochondrial-DNA level. Our analyses indicate that the dynamics of patrilineal descent groups, which implies different male and female sociodemographic histories, is responsible for these sexually-asymmetric genetic patterns. This molecular signature of the pastoral social organization disappears over a few centuries only after conversion to an agricultural way of life.

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