La Bastida
© Dani Méndez-REVIVES
A 3D reconstruction of La Bastida, one of the ancient sites from which samples were studied. The economy of La Bastida would have been more productive than other Argaric sites due to their fields being fertilised regularly by the grazing of livestock. The site's layout provide strong evidence of a marked social hierarchy
The El Algar society thrived in complex hilltop settlements across the Iberian Peninsula from 2200-1550 cal BCE, and gravesites and settlement layouts provide strong evidence of a marked social hierarchy.

Knipper and colleagues conducted carbon and nitrogen isotope analysis at two different El Algar hilltop settlements: the large fortified urban site La Bastida (in present-day Totana, Murcia), and the smaller settlement Gatas (Turre, Almería). Their sample included remains of 75 human individuals from across social strata, 28 bones from domestic animals and wild deer, charred barley (75 grains total), and charred wheat (29 grains) from the middle and late phases of El Algar civilization across the two sites.

La Bastida
© Daily Mail
The sampled human individuals showed no significant difference between isotope values for males and for females, suggesting that diets may have been similar between genders. However, "elite" individuals at La Bastida showed higher levels of both carbon and nitrogen. This might have implied that the people of La Bastida consumed higher levels of animal-based food, but the authors suggest that the isotope value differences between La Bastida and Gatas could in fact have resulted from similar dietary compositions. Nitrogen values are similar at both sites for barley, but higher for the domestic animals at La Bastida, meaning that diets with similar relative contributions of barley and meat/dairy products would have led to higher nitrogen values in the humans at La Bastida compared to Gatas.
La Bastida

Location of the site of La Bastida between the mountain ranges of Espuña and La Tercia, Spain. The arrow marks the summit of the hilltop settlement
The researchers found a strong reliance on cereal farming, supplemented by livestock, in the El Algar economy. The range and values of carbon in the barley and wheat sample reflect what was likely a dry, unirrigated landscape, though nitrogen levels in the cereal crops suggest the El Algar people applied animal manure to their fields. Cereals and their by-products appear to have contributed substantially to the forage of domesticated sheep/goats, cattle and pigs.

Though the sample used in this study* is relatively small, and there are limitations to what can be sampled with this type of isotope analysis, this study shows the importance of considering the complete trophic chain in order to adequately interpret isotope data from human remains-and also demonstrates the sophistication of El Algar farming techniques.

Knipper adds: "It is essential to not only investigate human remains, but also comparative samples of different former food stuffs as well as to interpret the data in the light of the archaeological and social historical context."
La Bastida

Tomb at La Bastida - a ceramic vessel that had been used to store grain used in the burial of an adult woman. Tomb 21 of La Bastida
Article Source: PLOS One news release

*Knipper C, Rihuete-Herrada C, Voltas J, Held P, Lull V, Micó R, et al. (2020) Reconstructing Bronze Age diets and farming strategies at the early Bronze Age sites of La Bastida and Gatas (southeast Iberia) using stable isotope analysis. PLoS ONE 15(3): e0229398. https://doi.org/10.1371/journal.pone.0229398