"Unearthing the Diets of Our Ancestors: Technological Advances in the Study of Early Hominin Nutrition"
By Isaac W. Hubbell
Within the “discussion” section of the study, “Changing perspectives on early hominin diets” performed by (Teaford et al.), details the emerging paradigm shift that is taking place with regards to how we have viewed the diets of our earlier ancestors.
“Here we provide a brief review of the approaches that have been used to provide direct evidence of the diets consumed by individual extinct hominins (so-called foodprints), i.e., analyses of 1) phytoliths and genetic biomarkers incorporated into the dental calculus of fossil teeth, 2) dental microwear analyses, and 3) stable isotopes found in fossil tooth enamel. In each case, we review recent developments that may shed light on broader aspects of early hominin paleoecology, for instance, the potential to detect seasonal and/or interannual shifts in diet, dietary fluctuations in response to fine-scale climatic shifts, habitat differences, and possible niche partitioning among extinct taxa.”
Their thesis claims that with the utilization of modern techniques of analysis and technological advancements, major changes in early hominin diets and behaviors are becoming more evident.
Methodology
(Teaford et al.) employ a comprehensive multi-faceted strategy to delve into the dietary habits of early hominins. This approach merges different forms of research methods in order to construct a more detailed and data-driven understanding of ancient diets of hominins. Their study opens with traditional morphological studies which analyze the fossilized remains of early hominins, with a particular focus on the morphology of teeth. This includes evidence based on the shape and make up of teeth, which then provides clues involving the types of food these species could have consumed. Their study leveraged advancements in technology in order to perform dental topographic analyses. This process allows for a more precise measurement of the differences and similarities of the teeth.
Their research also incorporates carbon isotope data analysis. This very technique has been essential in distinguishing between the consumption of C3 and C4 plants by examining the carbon isotopic composition in the enamel of fossilized teeth. This analysis has been applied to well over 277 fossils that represent somewhere between 11 and 13 separate hominin species, to gauge the extent of C4 plant consumption among African hominins throughout history. The study of biogeochemistry is another pillar of the research, examining the chemical signatures found in biological tissues to deduce dietary habits. This field encompasses the study of the interactions between chemical, physical, geological, and biological processes that define the natural environment.
The study then utilizes dental calculus and microwear analysis to gain insight into the actual foods consumed by individual hominins. Dental calculus, or tartar, has the ability to capture and preserve remnants of food, whereas the patterns of microwear on teeth reveals the types of food processed and the chewing behaviors associated with them. They also examined craniodental functional morphology. This process analyses the size, shape, and structure of skulls and teeth to then infer the evolutionary history and functional adaptations of these species. By utilizing these techniques, the researchers were able to frame the dietary possibilities within specific evolutionary contexts. By integrating evidence of short-term dietary habits, such as direct methods or "food-prints," with long-term dietary inferences from morphological and biomechanical analyses, (Teaford et al.) study aims to provide a more intricate understanding of the diets of early hominins. This approach that their research takes, not only considers the actual foods consumed by individuals but also the broader evolutionary adaptations of the species over time.
Findings and Conclusions
The research of (Teaford et al.) focused on the eating habits of early hominins has revealed a significant transition to a diet rich in C4 plants across several species, including Paranthropus aethiopicus and its descendant Paranthropus boisei, as well as members of the Australopithecus and Homo groups. This shift in diet did not coincide with the development of new features in their teeth or jaws, implying that these hominins adapted to new food sources using their existing physical characteristics.
The findings of (Teaford et al.) coincide and are backed by research performed in a multitude of sites across Africa involving the paleoecology and its effect on Paranthropus and Homo evolution/adaptation. Their findings, specifically in regard to confirmed gradual vegetation changes in regions, such as West Turkana, suggest that extensive amounts of C4 grasses were indeed available across sub-Saharan Africa. It also shows that these grasses were beginning to appear, en-masse, around the time that Paranthropus and Homo split and were adapting to new ecological environments. While their study doesn’t confirm specifically that this was the primary diet of early hominins, it does support that the large-scale availability of these grasses was indeed there. This shows that hominins would not have specifically needed to change their teeth morphology before consuming these abundant grasses (Fillion and Harrison).
(Teaford et al) study of calcium isotopes has been particularly revealing, showing a trend of decreasing δ44/42Ca ratios higher up in the food chain. A. anamensis and Kenyanthropus platyops seemed to have diets similar to other East African browsers, while P. boisei had a unique dietary signature, enriched in 44Ca, which suggests a diet that possibly included certain wetland plants.
The task of piecing together the diets of these ancient beings is fraught with difficulties, stemming from the complexity of primate diets, the inconsistent preservation of fossils, and the vastly intricate layering of archaeological deposits. While current methods provide clues about what these early hominins may have eaten, they do also then fall short of confirming the specific foods they consumed. To overcome these challenges, the researchers of the study propose a comprehensive approach that combines direct dietary evidence, such as biogeochemical data and analysis of dental wear, with indirect evidence from the study of fossil morphology and biomechanics. This integrated approach is essential for a deeper understanding of the dietary habits and environmental adaptations of early hominins, offering valuable insights into their evolutionary journey and lifestyle.
Bibliography:
Fillion, Elizabeth N., and Terry Harrison. “Mixed Models Elucidate Local- and Regional-Scale Drivers of Paleoenvironmental Change in Eastern Africa during the Emergence of Paranthropus and Homo.” Palaeogeography, Palaeoclimatology, Palaeoecology, vol. 616, 15 Apr. 2023, p. 111479, www.sciencedirect.com/science/article/abs/pii/S0031018223000974, https://doi.org/10.1016/j.palaeo.2023.111479. Accessed 19 Feb. 2024.
Teaford, Mark F., et al. “Changing Perspectives on Early Hominin Diets.” Proceedings of the National Academy of Sciences, vol. 120, no. 7, 6 Feb. 2023, https://doi.org/10.1073/pnas.2201421120.