Research master thesis | Archaeology (research) (MA/MSc)
open access
Diet has been one of the main drivers in the origin, evolution, and behaviour of our ancestors. Key moments in our evolutionary trajectory have been linked to changes in diet. These evolutionary...Show moreDiet has been one of the main drivers in the origin, evolution, and behaviour of our ancestors. Key moments in our evolutionary trajectory have been linked to changes in diet. These evolutionary developments include an increase in brain size, changes in habitat choice, adaptations in body size, and changes in life history. However, the Pleistocene archaeological record is highly fragmentary. To complement this lack of data, archaeology and ethnography have been combined for over decades. The predominant part of studies investigating early Homo subsistence behaviours and nutrition have focused on extant foraging populations from the African savannas to develop substantial models of human behavioural evolution. Though, studies focusing on hunter-gatherer nutrition have significantly undervalued the variability that is present within foraging diets. Furthermore, the rainforest-type environment is largely rejected its crucial role in the evolution of our lineage. The predominant part of studies have based their analyses on large-scale dietary indexes. Some authors have assumed that taken on aggregate, the average hunter-gatherer dietary profile can be recruited as a universal, ancestral diet. This led to the formation of the so-called Paleodiet movement, that attempts to help solve and understand public health issues known as the diseases of civilization such as obesity, diabetes, and other non-communicable diseases. However, it remains unclear what a uniform, ancestral Paleodiet should look like, or whether such a concept is feasible. Here, we show that hunter-gatherer nutrition is highly variable in nature, and that no uniformly applicable Paleodiet exists. By conducting a high-resolution macronutrient analysis on 30 wild edible plant taxa used by the Baka forager-horticulturalists from Southeastern Cameroon, we have shown that the nutritional qualities of wild edible plants are greatly affected by the effects of habitat and plant age, on a within- and between species level. Furthermore, we found that previously established aggregate hunter-gatherer nutritional profiles greatly differ from the reconstructed dietary- and macronutrient profiles established for the Baka. As Baka rainforest nutrition could be reverse-engineered, we illustrate that the Congo Basin rainforest-type environment provides enough macronutrients for hominins to sustain themselves without the aid of agriculture, and that the rainforest-type environment has been a crucial environment for the evolution of our lineage. Carbohydrates from starchy tubers are proposed to play a key role in Baka nutrition. Such underground storage organs are argued to have been important to early hominin nutrition within African rainforests. Public health studies may benefit by shifting their focus towards other components of Western lifestyle as more important contributors to diseases of civilization such as physical activity, stress, time spent outdoor, and overconsumption. We anticipate that future studies on extant foraging diet may greatly benefit from supplementing their use of large-scale hunter-gatherer nutritional indexes with high-resolution chemical nutritional data, as well as data 148 on weight of food brought back to camp, and estimated consumption patterns, to broaden our understanding on Pleistocene subsistence behaviour. We stimulate other research to partake in multi-disciplinary discourse for more increasingly diverse and inclusive narratives on human nutrition, Pleistocene subsistence behaviours, and human evolution. Lastly, to fully understand the influences of hominin dietary practices on the trajectory of our own evolution, it is imperative to acknowledge the plurality of both extant- and extinct hunter-gatherer lifeways, and to project a similar range of variability onto Pleistocene behaviours across different habitats.Show less
The origin of speech is one of the biggest unanswered questions in the evolution of mankind. Scientist from all over the world from different disciplines using different methodologies have been...Show moreThe origin of speech is one of the biggest unanswered questions in the evolution of mankind. Scientist from all over the world from different disciplines using different methodologies have been trying to solve the mystery that is the origin of speech. An unambiguous answer however, remains absent. Using the method of comparative morphology and microbiomechanical studies, it can be studied when in our evolutionary history the anatomy fit to support speech production first arose, and thus which species first had the ability to talk. This thesis looks at published data on different hard structures of the vocal tract, in particular the hyoid, hard palate and mandible, of Australopithecus afarensis, Homo erectus, the SH hominins and Homo neanderthalensis to compare them to those of the modern human and non-human great apes vocal tract, in order to discover what we can infer about the origin speech based on the evolution of the vocal tract. This comparison has shown that based on their features, these hominins can be divided into two categories. The first category is that of archaic morphology and is characterized by a hyoid, hard palate and mandible that most closely resembles the anatomical features of the non-human great apes, in particular, chimpanzees. This means they possessed a bullashaped hyoid body, a long and broad hard palate and a long and narrow, chinless mandible. To this group belong the Australopithecus afarensis and Homo erectus. The second category is that of modern morphology and is characterized by the hyoid, hard palate and mandible that most closely resembles the anatomical features of modern humans. This means a bar-like hyoid body, a shorter and more narrow hard palate and a short and broad mandible with a bony protuberance, the chin. To this groups belongs the SH hominins the Homo neanderthalensis. Based on the results, it can be concluded that the anatomical features of the vocal tract fit to support the production of speech were already in place with, at least, Neanderthals. Therefore, Neanderthals could speak. The way forward for future studies into the origin of speech mainly is more data, both in terms of quantity and more species, though this is not something that can be forced. Establishing the origin of speech might open up a new path into studying the origin of language, a related, but not identical topic.Show less
Umhlatuzana rock shelter is a site first excavated in the 1980s located in the ZwaZulu-Natal province, South Africa. About 70.000 years of human activity are represented at the site without...Show moreUmhlatuzana rock shelter is a site first excavated in the 1980s located in the ZwaZulu-Natal province, South Africa. About 70.000 years of human activity are represented at the site without occupational hiatuses, which is rarely found in the region. A recent (2018-2019) fieldwork campaign by a team from Leiden University has unearthed thousands of lithic artefacts dating between the Middle Stone Age and Later Stone Age. This thesis aims to determine the raw material composition of a sample of 100 recently excavated lithics, coming from two different spits dating to the end of the Howiesons Poort and to the Late Middle Stone Age periods. The results from the two spits are compared to identify any chronological patterns of variation. The results are then related to the raw material proportions reported from the first excavation. A combination of visual and geochemical (PXRF) analyses is used to identify different rock types and to test the accuracy of visual determination for raw material classification. The main rock types identified in the sample are hornfels, sandstone and quartz, accompanied in smaller amounts by other materials such as quartzite and ironstone. The data obtained suggests continuity in raw material choice from the Howiesons Poort to the Late MSA period and purposefulness in the selection of different rock types for different uses. The evidence aligns in this aspect with other nearby sites, such as Sibudu and Umbeli Belli. The exact raw material proportions of the spits, however, are unlike what is seen elsewhere, and do not conform with the results presented by J. Kaplan, the original excavator of the site. Raw material choice is fundamental to the toolmaking process and integral to our understanding of past hunter-gatherer lifeways. The study presented here adds to a growing body of evidence on the southern African Middle Stone Age, furthering the current knowledge on the behaviors of early Modern Humans.Show less
Decades of research on the role and frequency of fire use in human evolution have only yielded a blurred understanding of the chronology of anthropogenic fire practise. This predicament has by and...Show moreDecades of research on the role and frequency of fire use in human evolution have only yielded a blurred understanding of the chronology of anthropogenic fire practise. This predicament has by and large resulted from an ambiguous archaeological record, issues of preservation of fire residues, as well as undefined frameworks for the scientific study of anthropogenic fire. In fact, besides stirring scholarly debates that in many ways has produced more heat than light, very little actual progress has been made in the last decade with regards to the general understanding of when and where various fire practices (i.e. controlled, opportunistic, and habitual) have emerged. Instead, variable length chronologies have been developed in which various researchers read and interpret the same evidence of fire in a variety of ways. This thesis sets out to add some clarity to the debate by 1) providing a comparative analysis of the various chronologies, with a focus on testing the strengths and weaknesses of the shorter chronologies against the wider background of fire evidence, i.e. the long chronologies; 2) by examining major challenges hindering any considerable progress in establishing a sound and agreed upon chronological framework for fire use and its subsequent production during the Pleistocene Period; and 3) by providing practical solutions and suggestions on directions for future research.Show less
