Julie Dunne

First dairying in green Saharan Africa in the fifth millennium bc

In the prehistoric green Sahara of Holocene North Africa—in contrast to the Neolithic of Europe and Eurasia—a reliance on cattle, sheep and goats emerged as a stable and widespread way of life, long before the first evidence for domesticated plants or settled village farming communities. The remarkable rock art found widely across the region depicts cattle herding among early Saharan pastoral groups, and includes rare scenes of milking; however, these images can rarely be reliably dated. Although the faunal evidence provides further confirmation of the importance of cattle and other domesticates, the scarcity of cattle bones makes it impossible to ascertain herd structures via kill-off patterns, thereby precluding interpretations of whether dairying was practiced. Because pottery production begins early in northern Africa the potential exists to investigate diet and subsistence practices using molecular and isotopic analyses of absorbed food residues. This approach has been successful in determining the chronology of dairying beginning in the ‘Fertile Crescent’ of the Near East and its spread across Europe. Here we report the first unequivocal chemical evidence, based on the δ13C and Δ13C values of the major alkanoic acids of milk fat, for the adoption of dairying practices by prehistoric Saharan African people in the fifth millennium bc. Interpretations are supported by a new database of modern ruminant animal fats collected from Africa. These findings confirm the importance of ‘lifetime products’, such as milk, in early Saharan pastoralism, and provide an evolutionary context for the emergence of lactase persistence in Africa.

Widespread exploitation of the honeybee by early neolithic farmers

The pressures on honeybee (Apis mellifera) populations, resulting from threats by modern pesticides, parasites, predators and diseases, have raised awareness of the economic importance and critical role this insect plays in agricultural societies across the globe. However, the association of humans with A. mellifera predates post-industrial-revolution agriculture, as evidenced by the widespread presence of ancient Egyptian bee iconography dating to the Old Kingdom (approximately 2400 bc). There are also indications of Stone Age people harvesting bee products; for example, honey hunting is interpreted from rock art in a prehistoric Holocene context and a beeswax find in a pre-agriculturalist site. However, when and where the regular association of A. mellifera with agriculturalists emerged is unknown. One of the major products of A. mellifera is beeswax, which is composed of a complex suite of lipids including n-alkanes, n-alkanoic acids and fatty acyl wax esters. The composition is highly constant as it is determined genetically through the insect’s biochemistry. Thus, the chemical ‘fingerprint’ of beeswax provides a reliable basis for detecting this commodity in organic residues preserved at archaeological sites, which we now use to trace the exploitation by humans of A. mellifera temporally and spatially. Here we present secure identifications of beeswax in lipid residues preserved in pottery vessels of Neolithic Old World farmers. The geographical range of bee product exploitation is traced in Neolithic Europe, the Near East and North Africa, providing the palaeoecological range of honeybees during prehistory. Temporally, we demonstrate that bee products were exploited continuously, and probably extensively in some regions, at least from the seventh millennium cal bc, likely fulfilling a variety of technological and cultural functions. The close association of A. mellifera with Neolithic farming communities dates to the early onset of agriculture and may provide evidence for the beginnings of a domestication process.

Earliest direct evidence of plant processing in prehistoric Saharan pottery

The invention of thermally resistant ceramic cooking vessels around 15,000 years ago was a major advance in human diet and nutrition1–3, opening up new food groups and preparation techniques. Previous investigations of lipid biomarkers contained in food residues have routinely demonstrated the importance of prehistoric cooking pots for the processing of animal products across the world4. Remarkably, however, direct evidence for plant processing in prehistoric pottery has not been forthcoming, despite the potential to cook otherwise unpalatable or even toxic plants2,5. In North Africa, archaeobotanical evidence of charred and desiccated plant organs denotes that Early Holocene hunter-gatherers routinely exploited a wide range of plant resources6. Here, we reveal the earliest direct evidence for plant processing in pottery globally, from the sites of Takarkori and Uan Afuda in the Libyan Sahara, dated to 8200–6400 bc. Characteristic carbon number distributions and δ13C values for plant wax-derived n-alkanes and alkanoic acids indicate sustained and systematic processing of C3/C4 grasses and aquatic plants, gathered from the savannahs and lakes in the Early to Middle Holocene green Sahara.

From the inside out: Upscaling organic residue analyses of archaeological ceramics

Abstract The investigation of organic residues associated with archaeological pottery using modern analytical chemical methods began in the 1970s. It was recognised early on that the analysis of lipids (i.e. fats, waxes and resins) preserved in surface residues or the fabric of single potsherds, representative of single vessels, was a powerful method for ascertaining pottery use, with a high degree of specificity. Subsequent developments saw a significant change in scale, with studies often involving lipid analyses of tens to hundreds of potsherds per archaeological assemblage, providing information that extended beyond pottery use. The identification of animal and plant foodstuffs processed in pots provides insights into herding and farming, and can also detect trade in exotic organic goods. Information about the environment and climate can be extrapolated from the isotopic composition of compounds detected in potsherds, potentially providing novel avenues of investigation. The direct dating of lipids in potsherds is opening up new opportunities for building archaeological chronologies, while the integration of lipid residue analyses with other environmental and cultural proxies within interdisciplinary projects is already providing unprecedented insights into past lifestyles, from site to regional scales.

Ancient biomolecules and evolutionary inference

Over the past three decades, studies of ancient biomolecules-particularly ancient DNA, proteins, and lipids-have revolutionized our understanding of evolutionary history. Though initially fraught with many challenges, today the field stands on firm foundations. Researchers now successfully retrieve nucleotide and amino acid sequences, as well as lipid signatures, from progressively older samples, originating from geographic areas and depositional environments that, until recently, were regarded as hostile to long-term preservation of biomolecules. Sampling frequencies and the spatial and temporal scope of studies have also increased markedly, and with them the size and quality of the data sets generated. This progress has been made possible by continuous technical innovations in analytical methods, enhanced criteria for the selection of ancient samples, integrated experimental methods, and advanced computational approaches. Here, we discuss the history and current state of ancient biomolecule research, its applications to evolutionary inference, and future directions for this young and exciting field.

Diet and Subsistence Practices in Holocene North Africa: An Integrated Archaeological, Molecular and Isotopic Approach

relatively constant throughout the last 18,000 years, greater functional variability among bone points is evident during the last 6000 years and largely parallels the sustained focus on hunting smaller animals. Changes in bone tool form and function do not correlate neatly with lithic technology oscillations or with environmental fluctuations and seem to occur during, rather than at the boundaries of, stone tool technocomplexes. Evidence that bone points were reused after they fractured suggests the importance attached to these tools and their raw material. Finally, a range of different arrow forms are recognised that may have the potential to provide an avenue for relative dating.