Periodic Reporting for period 2 - DEMETER (Eight millennia of changes in domestic plants and animals: understanding local adaptation under socio-economic and climatic fluctuations)
Reporting period: 2021-09-01 to 2023-02-28
The domestication of plants and animals marks a major transition in human history and is a key element in the development of modern societies. Local and traditional domestic breeds and varieties are the result of millennia of selection of landraces by farmers. However, we are now experiencing a major crisis with a drastic loss in the diversity of food production systems and the progressive disappearance of traditional practices. The local knowledge and culture of farmers are under threat, as well as the diversity of crop species, varieties and breeds. In this context, DEMETER’s objective is to trace how societies influenced the evolution of domestic species under different farming, environmental regimes, and socio-economic contexts since the onset of agriculture, focusing primarily on the North-Western Mediterranean basin. More specifically, DEMETER aims at identifying: 1) how and why the diversity of domestic forms evolved and led to the large number of breeds and varieties that exist today, and 2) how this agrobiodiversity and its evolution relate to the environmental and socio-economic changes that occurred repeatedly since the onset of agriculture. DEMETER aims at studying the evolution, from the Neolithic until the present, of selected animal and plant models: pigs, sheep, goats and barley, in a given region, the Northwestern Occidental Mediterranean basin, i.e. outside their primary ‘domestication centre’. DEMETER is based on an unprecedented and unconventional combination of approaches, including archaeophenomics (through geometric morphometrics), databasing, zooarchaeology, archaeobotany, proxies-based paleoclimate reconstructions, palaeoproteins (ZooMs) and statistical analyses, implemented primarily on archaeological mammal teeth and barley grains.
DEMETER will produce an unique regional synthesis of the relationships between humans and domesticates over the last 8 millennia in a new way and at a fine-scale resolution never envisioned before.
DEMETER will produce an unique regional synthesis of the relationships between humans and domesticates over the last 8 millennia in a new way and at a fine-scale resolution never envisioned before.
To address the questions of DEMETER, this first half of the project has focused on the following steps:
- Compiling archaeozoological data from 472 sites (number of remains, mortality profiles, archaeological contextualization, biometry)
- Compiling archaeobotanial data from 247 sites (Number of remains, archaeological contextualization)
- Compiling ecological trait data for the species or group of species recovered in the archaeobotanical records
- Compiling archaeological context data (e.g. type of occupation, dating) for the studied sites
- Reconstructing paleoclimate changes for the region (i.e. from pollen and molecular biomarkers as brGDGTs obtained from sedimental cores)
- Acquisition of a total of 17056 phenomes (plants and animals, modern and archaeological) through geometric morphometrics
- Developing tools for identifying ancient remains (i.e. morphometrics and palaeoproteins)
- Reconstructing size evolution of the domestic triad during Antiquity in Languedoc as a first case study of the diachronic evolution of domestic mammals in the region
- Compiling archaeozoological data from 472 sites (number of remains, mortality profiles, archaeological contextualization, biometry)
- Compiling archaeobotanial data from 247 sites (Number of remains, archaeological contextualization)
- Compiling ecological trait data for the species or group of species recovered in the archaeobotanical records
- Compiling archaeological context data (e.g. type of occupation, dating) for the studied sites
- Reconstructing paleoclimate changes for the region (i.e. from pollen and molecular biomarkers as brGDGTs obtained from sedimental cores)
- Acquisition of a total of 17056 phenomes (plants and animals, modern and archaeological) through geometric morphometrics
- Developing tools for identifying ancient remains (i.e. morphometrics and palaeoproteins)
- Reconstructing size evolution of the domestic triad during Antiquity in Languedoc as a first case study of the diachronic evolution of domestic mammals in the region
The DEMETER project aims at understanding HOW and WHY the domestic species evolved in a region, outside the core domestication center, from the arrival of agriculture. The focus of the DEMETER project is the North Western Mediterranean basin (Catalonia and South of France) where the Neolithic and the first domesticated species (beyond dog) arrived ~8000 years ago. To be able to disentangle the different factors that shape the domestic diversity through time, i.e. human cultures and techniques, geography, climate, time itself, of a large quantity of data needs to be gathered and compiled. The core species of the DEMETER project are sheep, goat, pig and barley, as models of domesticated species.
During the initial phases of the DEMETER project, we have successfully gathered a strong network of collaborators of various expertises (climat modellers, archaeobotanists, archaeozoologists, archaeologists, historians). We have built an unprecedent bioarchaeological database for the region that will provide all the data necessary to disentangle the factors that may have shape the agrobiodiversity and its evolution. We have collected more than 17000 phenomes, quantified through geometric morphometrics, of modern and archaeological barley grains and mammal teeth, going beyond our initial objectives, but also far beyond existing datasets. Sheep and goat are particularly difficult to identify in the archaeological records because of the fragmentary nature of the archaeozoological material but also because of the close anatomical proximity between these species. We have developed new tools for identifying isolated lower third molars and mandibles, that are commonly found in the archaeological records. We will combine the morphometric identification of the archaeological specimens with biomolecular identifications provided by a ZooMs approach (palaeoproteines), a comparison that has never been done before. For barley, for which the grains are usually found charred and often in large number, we are using a large reference collection of French and Mediterranean varieties and fine scaled morphometric description of the grain morphometry to assess the complex diversity of the cereal (e.g. hulled/naked, 2row/6row). This allows us to develop new tools for identifying ancient grains, and follow the evolution of grain morphology. By the end of the project we will have developed and validated morphometric databases (one per species, or complex of species) that could be used beyond the DEMETER project.
Archaeological studies often study and compare chronocultural phases (e.g. Neolithic) but one of the specificities of DEMETER is to use time as a continuous variable, quantified by a mean and a range of occupation time (TPQ, TAQ). This has led to a first study exploring the evolution of size of the domestic triad (sheep, goat, pig) in Languedoc during Roman times that will be ultimately pursued to cover the last 8 millenia.
Because contrasting the morphometric variation with biotic and abiotic factors require careful characterization of the environmental and archaeological contexts, a large amount of effort has been made to contextualize the data as accurately as possible (at the stratigraphic unit stage in our case), but also to assess the external factors carefully. This is particularly the case for the climate for which we have worked on temperature reconstruction through the Holocene using both pollen data, as classically done, but also newly developed biomarkers. The confrontation of both will result in robust knowledge of temperature evolution, geographically structured (e.g. littoral vs altitude), that will be confronted to our morphometric data.
At this stage of the project, data acquisition is almost complete and the second part will be fully dedicated to the analyses.
By the end of the project we will produce an unique regional synthesis of the relationships between humans and domesticates over the last 8 millennia in a new way and at a fine-scale resolution never envisioned before.
During the initial phases of the DEMETER project, we have successfully gathered a strong network of collaborators of various expertises (climat modellers, archaeobotanists, archaeozoologists, archaeologists, historians). We have built an unprecedent bioarchaeological database for the region that will provide all the data necessary to disentangle the factors that may have shape the agrobiodiversity and its evolution. We have collected more than 17000 phenomes, quantified through geometric morphometrics, of modern and archaeological barley grains and mammal teeth, going beyond our initial objectives, but also far beyond existing datasets. Sheep and goat are particularly difficult to identify in the archaeological records because of the fragmentary nature of the archaeozoological material but also because of the close anatomical proximity between these species. We have developed new tools for identifying isolated lower third molars and mandibles, that are commonly found in the archaeological records. We will combine the morphometric identification of the archaeological specimens with biomolecular identifications provided by a ZooMs approach (palaeoproteines), a comparison that has never been done before. For barley, for which the grains are usually found charred and often in large number, we are using a large reference collection of French and Mediterranean varieties and fine scaled morphometric description of the grain morphometry to assess the complex diversity of the cereal (e.g. hulled/naked, 2row/6row). This allows us to develop new tools for identifying ancient grains, and follow the evolution of grain morphology. By the end of the project we will have developed and validated morphometric databases (one per species, or complex of species) that could be used beyond the DEMETER project.
Archaeological studies often study and compare chronocultural phases (e.g. Neolithic) but one of the specificities of DEMETER is to use time as a continuous variable, quantified by a mean and a range of occupation time (TPQ, TAQ). This has led to a first study exploring the evolution of size of the domestic triad (sheep, goat, pig) in Languedoc during Roman times that will be ultimately pursued to cover the last 8 millenia.
Because contrasting the morphometric variation with biotic and abiotic factors require careful characterization of the environmental and archaeological contexts, a large amount of effort has been made to contextualize the data as accurately as possible (at the stratigraphic unit stage in our case), but also to assess the external factors carefully. This is particularly the case for the climate for which we have worked on temperature reconstruction through the Holocene using both pollen data, as classically done, but also newly developed biomarkers. The confrontation of both will result in robust knowledge of temperature evolution, geographically structured (e.g. littoral vs altitude), that will be confronted to our morphometric data.
At this stage of the project, data acquisition is almost complete and the second part will be fully dedicated to the analyses.
By the end of the project we will produce an unique regional synthesis of the relationships between humans and domesticates over the last 8 millennia in a new way and at a fine-scale resolution never envisioned before.