Periodic Reporting for period 1 - BACBONE (Contrasting Neanderthal and modern human subsistence practices across Europe 50,000-40,000 years ago: an interdisciplinary approach to micro-scale taphonomy and BACterial bioerosion on BONE.)
Período documentado: 2022-02-01 hasta 2024-01-31
A key question in human evolution relates to behavioural differences between Neanderthals and early modern humans and to what extent these may have contributed to the eventual extinction of Neanderthals in Eurasia ca. 40,000 years ago. Past hypotheses have emphasised the importance of distance hunting and a broadening of the diet as key factors in the global success of modern humans. In order to understand this requires the detailed data on differences in subsistence practices and diet through the identification and analysis of fragmented animal bones from Palaeolithic sites.
Typically, these studies focus on morphologically identifiable bones, representing only 10-30% of a faunal assemblage and on visible and well documented bone surface modifications. Since 2009, zooarchaeology has benefitted from the development of biomolecular methods, especially Zooarchaeology by Mass Spectrometry (ZooMS). ZooMS provides taxonomic identifications of morphologically unidentifiable bone fragments. With a success rate of 95%, ZooMS greatly increases the number of taxonomically identified bones at a site. Alongside biomolecular advances there has been a renewed focus on the analysis of the microscopic alteration to bone (histotaphonomy), which can have direct behavioural implications. Results can illustrate whether bones entered the archaeological record butchered or fully fleshed (complete carcass burial or natural death), though these have, largely, focused on human remains from more recent time periods.
BACBONE is the first large-scale histotaphonomic study of Palaeolithic bone assemblages, combining taxonomic identifications through ZooMS with hard tissue histology and the high-throughput capacity of high-resolution microtomography (micro-CT) for non-destructive virtual histology. BACBONE cross-compares the histotaphonomic signature of various animal species (e.g. butchered herbivore vs natural carnivore death) with available human remains to facilitate an unparalleled comprehensive reconstruction of bone deposition and processing patterns. The project has developed a unique methodology, which has identified histotaphonomic characteristics using both non-destructive virtual histology and hard-tissue histology. These methods were applied to a wide range of materials from sites of different time periods and producing exciting results and a clear methodological pathway for future development and application.
Typically, these studies focus on morphologically identifiable bones, representing only 10-30% of a faunal assemblage and on visible and well documented bone surface modifications. Since 2009, zooarchaeology has benefitted from the development of biomolecular methods, especially Zooarchaeology by Mass Spectrometry (ZooMS). ZooMS provides taxonomic identifications of morphologically unidentifiable bone fragments. With a success rate of 95%, ZooMS greatly increases the number of taxonomically identified bones at a site. Alongside biomolecular advances there has been a renewed focus on the analysis of the microscopic alteration to bone (histotaphonomy), which can have direct behavioural implications. Results can illustrate whether bones entered the archaeological record butchered or fully fleshed (complete carcass burial or natural death), though these have, largely, focused on human remains from more recent time periods.
BACBONE is the first large-scale histotaphonomic study of Palaeolithic bone assemblages, combining taxonomic identifications through ZooMS with hard tissue histology and the high-throughput capacity of high-resolution microtomography (micro-CT) for non-destructive virtual histology. BACBONE cross-compares the histotaphonomic signature of various animal species (e.g. butchered herbivore vs natural carnivore death) with available human remains to facilitate an unparalleled comprehensive reconstruction of bone deposition and processing patterns. The project has developed a unique methodology, which has identified histotaphonomic characteristics using both non-destructive virtual histology and hard-tissue histology. These methods were applied to a wide range of materials from sites of different time periods and producing exciting results and a clear methodological pathway for future development and application.
BACBONE has focussed on the development of a methodology to fully exploit the potential of bone assemblages from archaeological sites and as such has focused on bone material from recent and Palaeolithic sites.
Firstly, using bone material from the Medieval site of St Gregory’s Priory, stored within the host institution, I undertook an intensive 6-12 month period of training through research to learn and apply the novel techniques of micro-CT scanning and hard-tissue histology. I conducted a visual assessment of human burial material to identify potential candidates to illustrate evidence for bioerosion. I then conducted virtual histology (using micro-CT scanning) to identify and record the presence and distribution of bacterial bioerosion and confirmed this using hard-tissue histology. To provide context for the human material I also scanned animal bones from the same site. I recorded several semi-quantitative measures including Oxford Histological Index, General Histological Index and the newly developed Virtual Histological Index. While bioeroded bone was more prevalent in the human specimens I also identified this in the animal bones, though differences in intensity and distribution potentially suggesting different accumulation scenarios.
This visibility of bacterial bioerosion in this assemblage lead to the development of a related research pathway to investigate its origin, through the study of ancient DNA (aDNA). This used the same samples from St Gregory’s Priory and sampled locations based either in areas with good or poor bone preservation. This was to identify and synthesise bacterial aDNA and compare this with know mammalian and human gut microbiome. This will lead to the establishment further collaborations to try to extract additional ancient DNA and palaeoproteomic data.
In the final part of the project I applied the new techniques and methodologies to bone material from a range of Palaeolithic sites. I selected ZooMS identified samples from Ranis (Germany) and Abri Moula (France) for micro-CT scanning. At both sites I selected animal and human fragments to cover the range of potential burial scenarios (butchered vs. complete carcass). At Ranis the scans showed very little variation in bone density suggesting that either material buried very quickly or potential that bacterial bioerosion was subdued due to extremely cold environments. At Abri Moula, virtual histology has identified differences between animal and human remains suggesting evidence for the varied deposition. Further work stemmed from previous collaborations at Bacho Kiro Cave (Bulgaria). I scanned soil micromorphology blocks, which included large quantities of sediment, lithic and bone material. Using micro-CT scanning I was able to identify and distinguish bone remains from other inclusions and identify bones with bioerosion allowing for future targeted identification through ZooMS and aDNA.
The results of this project are detailed in a series of papers in open-access peer-reviewed journals (published, in press, in preparation) and have also been presented at various international conferences. As part of BACBONE I also developed and supervised an undergraduate dissertation project on bacterial bioerosion from St Gregory’s Priory. I hosted a workshop on integrating ZooMS and zooarchaeology data to provide further in-depth data on past human diet and ecology (https://www.palaeozooarch.com/workshops).
Firstly, using bone material from the Medieval site of St Gregory’s Priory, stored within the host institution, I undertook an intensive 6-12 month period of training through research to learn and apply the novel techniques of micro-CT scanning and hard-tissue histology. I conducted a visual assessment of human burial material to identify potential candidates to illustrate evidence for bioerosion. I then conducted virtual histology (using micro-CT scanning) to identify and record the presence and distribution of bacterial bioerosion and confirmed this using hard-tissue histology. To provide context for the human material I also scanned animal bones from the same site. I recorded several semi-quantitative measures including Oxford Histological Index, General Histological Index and the newly developed Virtual Histological Index. While bioeroded bone was more prevalent in the human specimens I also identified this in the animal bones, though differences in intensity and distribution potentially suggesting different accumulation scenarios.
This visibility of bacterial bioerosion in this assemblage lead to the development of a related research pathway to investigate its origin, through the study of ancient DNA (aDNA). This used the same samples from St Gregory’s Priory and sampled locations based either in areas with good or poor bone preservation. This was to identify and synthesise bacterial aDNA and compare this with know mammalian and human gut microbiome. This will lead to the establishment further collaborations to try to extract additional ancient DNA and palaeoproteomic data.
In the final part of the project I applied the new techniques and methodologies to bone material from a range of Palaeolithic sites. I selected ZooMS identified samples from Ranis (Germany) and Abri Moula (France) for micro-CT scanning. At both sites I selected animal and human fragments to cover the range of potential burial scenarios (butchered vs. complete carcass). At Ranis the scans showed very little variation in bone density suggesting that either material buried very quickly or potential that bacterial bioerosion was subdued due to extremely cold environments. At Abri Moula, virtual histology has identified differences between animal and human remains suggesting evidence for the varied deposition. Further work stemmed from previous collaborations at Bacho Kiro Cave (Bulgaria). I scanned soil micromorphology blocks, which included large quantities of sediment, lithic and bone material. Using micro-CT scanning I was able to identify and distinguish bone remains from other inclusions and identify bones with bioerosion allowing for future targeted identification through ZooMS and aDNA.
The results of this project are detailed in a series of papers in open-access peer-reviewed journals (published, in press, in preparation) and have also been presented at various international conferences. As part of BACBONE I also developed and supervised an undergraduate dissertation project on bacterial bioerosion from St Gregory’s Priory. I hosted a workshop on integrating ZooMS and zooarchaeology data to provide further in-depth data on past human diet and ecology (https://www.palaeozooarch.com/workshops).
The disappearance of Neanderthal groups in western Eurasia ca.40,000 years ago remains a key question in human evolution. New methods are constantly refining our understanding of the chronology and behaviour of both late Neanderthal and early modern human groups especially in relation to variation in subsistence and diet. To do this requires the in-depth study of fragmented animal bones and the in depth recording of taphonomic modifications from Neanderthal and modern human sites. Understanding the variation and differences in subsistence and diet will help understand to what extent behavioural differences played a role in the replacement of Neanderthals by modern humans.
BACBONE represents a first step in our understanding of the micro-taphonomy of bone remains at archaeological sites. Bacterial bioerosion has the potential to provide novel data on site history and subsistence behaviour by investigating the micro-scale modification of bone. These modifications can be combined further with traditional zooarchaeological and macro-scale taphonomic data. The multi-method approach applied throughout the project can now take advantage of advancements in taxonomic identification through ZooMS and the high throughput capacity of micro-CT scanning. This allows for an initial, non-destructive assessment of the material before any future destructive hard-tissue histology can be applied. There is further potential for method development through the extraction and analysis of ancient DNA and ancient proteins from bioeroded material.
BACBONE represents a first step in our understanding of the micro-taphonomy of bone remains at archaeological sites. Bacterial bioerosion has the potential to provide novel data on site history and subsistence behaviour by investigating the micro-scale modification of bone. These modifications can be combined further with traditional zooarchaeological and macro-scale taphonomic data. The multi-method approach applied throughout the project can now take advantage of advancements in taxonomic identification through ZooMS and the high throughput capacity of micro-CT scanning. This allows for an initial, non-destructive assessment of the material before any future destructive hard-tissue histology can be applied. There is further potential for method development through the extraction and analysis of ancient DNA and ancient proteins from bioeroded material.