Periodic Reporting for period 1 - WEAN-IT (WEaning practices in ANcient ITaly: from Neolithic farmers to the first cities)
Período documentado: 2020-04-01 hasta 2022-03-31
Human growth and development, from the earliest phases of ontogenesis, is affected by dietary behaviour, including that of the mother during pregnancy.
From an historical perspective, the study of the strong connections among diet, adaptation, and culture, particularly during infancy and gestation, can offer an invaluable contribution for the reconstruction of the past societies. Indeed, the adoption of farming economies between the Early Holocene and the 4th millennium BCE was probably the greatest innovation in human history. As the new farmers, their ideas, and the new economies spread across space and time it led to altered social behaviours and changes to human biology. The new social structures that emerged laid the foundations for ancient urban societies and continue to influence the way that we live today. One of the pivotal moments of everyone life, i.e. weaning, was woven into these changes.
Indeed, gestation and breastfeeding are substantial energetic investments for the mothers and are constrained by access to food resources. The first introduction of foodstuffs in an infant’s diet – i.e. the onset of weaning – is pivotal in shaping the growth and health of infants. Weaning age directly reflects the way infants are cared for within a human society. It is linked to female fertility, maternal and non-maternal care strategies, social stratification, infant growth, and even adult health. Weaning age continues to be relevant for present day populations through policies issued by the World Health Organization. Yet, we know almost nothing about the way weaning age developed during recent human evolution.
The goal in this project was to reconstruct weaning age in extensive collections of human skeletons that span periods of transitions during recent human evolution. WEAN-IT uses a recent methodological development to trace elemental composition in dental enamel to identify the change from an exclusively breast milk diet to one that includes non-milk foods. The results derived from the integration of microstructural, histological, and chemical signals of weaning in milk teeth. Indeed, dental remains provide direct evidence of the initial infancy of humans at very high time resolution and carry the morpho-chemical signals of diet (including weaning), health, mobility, biorhythms, and the pace of growth from birth until the first years of life.
The overall objectives are: 1) to Identify the timing of weaning in modern human samples as a comparative benchmark for the ancient ones, 2) to determine the timing of weaning in archaeological skeletal populations, 3) to explore growth during weaning in both samples; and 4) to elucidate the social correlates of the changes in the timing of weaning.
Results of WEAN-IT, disseminated through many open-access articles and conferences, show - and will show in future publication - the feasibility and the importance of the project, highlighting a rather conservative, possibly biologically constrained, onset of weaning even in extinct human forms (Neanderthals) contrasting with a high variability of weanling food through time. This project adds value and competitiveness to the bioarchaeological research landscape in Europe, thanks to its innovative multi-methodological approach. Not only WEAN-IT is of interest to a broad range of academics within the social sciences, but it can inform present day public health policy as I will directly measure the effect of weaning on bone growth.
From an historical perspective, the study of the strong connections among diet, adaptation, and culture, particularly during infancy and gestation, can offer an invaluable contribution for the reconstruction of the past societies. Indeed, the adoption of farming economies between the Early Holocene and the 4th millennium BCE was probably the greatest innovation in human history. As the new farmers, their ideas, and the new economies spread across space and time it led to altered social behaviours and changes to human biology. The new social structures that emerged laid the foundations for ancient urban societies and continue to influence the way that we live today. One of the pivotal moments of everyone life, i.e. weaning, was woven into these changes.
Indeed, gestation and breastfeeding are substantial energetic investments for the mothers and are constrained by access to food resources. The first introduction of foodstuffs in an infant’s diet – i.e. the onset of weaning – is pivotal in shaping the growth and health of infants. Weaning age directly reflects the way infants are cared for within a human society. It is linked to female fertility, maternal and non-maternal care strategies, social stratification, infant growth, and even adult health. Weaning age continues to be relevant for present day populations through policies issued by the World Health Organization. Yet, we know almost nothing about the way weaning age developed during recent human evolution.
The goal in this project was to reconstruct weaning age in extensive collections of human skeletons that span periods of transitions during recent human evolution. WEAN-IT uses a recent methodological development to trace elemental composition in dental enamel to identify the change from an exclusively breast milk diet to one that includes non-milk foods. The results derived from the integration of microstructural, histological, and chemical signals of weaning in milk teeth. Indeed, dental remains provide direct evidence of the initial infancy of humans at very high time resolution and carry the morpho-chemical signals of diet (including weaning), health, mobility, biorhythms, and the pace of growth from birth until the first years of life.
The overall objectives are: 1) to Identify the timing of weaning in modern human samples as a comparative benchmark for the ancient ones, 2) to determine the timing of weaning in archaeological skeletal populations, 3) to explore growth during weaning in both samples; and 4) to elucidate the social correlates of the changes in the timing of weaning.
Results of WEAN-IT, disseminated through many open-access articles and conferences, show - and will show in future publication - the feasibility and the importance of the project, highlighting a rather conservative, possibly biologically constrained, onset of weaning even in extinct human forms (Neanderthals) contrasting with a high variability of weanling food through time. This project adds value and competitiveness to the bioarchaeological research landscape in Europe, thanks to its innovative multi-methodological approach. Not only WEAN-IT is of interest to a broad range of academics within the social sciences, but it can inform present day public health policy as I will directly measure the effect of weaning on bone growth.
Even though the COVID-19 pandemic impacted my project most of the original research objectives have been met. The project start date, which was April 2020 when the Covid-19 pandemic started, was delayed to September 2020. Year one of the project ran through two more lockdowns in the UK, which restricted access to the University of Kent, as well as travel to Italy to access the Italian archaeological collections. Despite this, I was able to pursue the main aims of my project, by changing the sampling strategy and data collection schedule. Indeed, during my project and despite the Covid-19 limitations, I collected a significant amount of histological and geochemical data from dental remains, that allowed me to reveal previously inaccessible aspects of childhood life in the past. Several milestones have been completed for histological and geochemical analyses as all this data have been collected, and a substantial portion of it has been analysed and already published or will be published in a short time. Project’s results so far published, in peer reviewed international journals or presented at international conferences, show the achievement of the proposed goals.
I acquired solid and broad technical skills in advanced methods for bioanthropology, particularly regarding the analysis of mineralized dental and bone tissues, and geochemical analyses of dental remains. Additionally, I deepened my knowledge on virtual histological analysis of dental tissues. These achievements are essential for my career development and to consolidate a holistic and interdisciplinary approach to the study of human odontoskeletal remains, which was one of the goals of my project. Finally, during my project I greatly improved my communication skills both in the academic environment and in a broader public, thanks to my outreach activities at the University of Kent and beyond.
All the project’s results have been published on high-impact, peer-reviewed journals (nine manuscripts, one more just accepted), presented at international conferences, or will be published in the short term (one manuscript in preparation). Moreover, I contributed to 14 podium and poster presentations at international conferences and one keynote invited talk at an international Workshop.
I acquired solid and broad technical skills in advanced methods for bioanthropology, particularly regarding the analysis of mineralized dental and bone tissues, and geochemical analyses of dental remains. Additionally, I deepened my knowledge on virtual histological analysis of dental tissues. These achievements are essential for my career development and to consolidate a holistic and interdisciplinary approach to the study of human odontoskeletal remains, which was one of the goals of my project. Finally, during my project I greatly improved my communication skills both in the academic environment and in a broader public, thanks to my outreach activities at the University of Kent and beyond.
All the project’s results have been published on high-impact, peer-reviewed journals (nine manuscripts, one more just accepted), presented at international conferences, or will be published in the short term (one manuscript in preparation). Moreover, I contributed to 14 podium and poster presentations at international conferences and one keynote invited talk at an international Workshop.
The interdisciplinary approach to weaning, merging histology and high-resolution chemical analysis into a single analytical toolkit, allowed me to merge biology, history, archaeology and anthropology, in order to reconstruct human past adaptations to the environment, in pre-historic and historic Italy (among the outputs of the project see: Nava et al 2020, PNAS, Lugli et al 2020, Journal of Archaeological Science: Reports, Gigante et al 2021, PlosOne, Mahoney et al 2021, Proceedings of the Royal Society B: Biological Sciences, Cerrito et al 2022, Journal of the Royal Society Interface, Lugli et al 2022, Scientific Reports, Nava et al 2022, Journal of Synchrotron Radiation). Results so far published, and the data collected during the project laid the ground for a new methodological approach in the study of weaning, and more generally on life conditions, in past human populations. My work also contributed to an extensive dataset on contemporary individuals that will be of major interest for public health (among the outputs of the project see: McFarlane et al 2021, Archives of Oral Biology, Mahoney et al, 2022, Communications Medicine).