Palaeoanthropologists have proposed that Neanderthals, the Middle Palaeolithic hominin occupant of Eurasia, differed from modern human relatives by having specialised diets focused on big game. A... Show morePalaeoanthropologists have proposed that Neanderthals, the Middle Palaeolithic hominin occupant of Eurasia, differed from modern human relatives by having specialised diets focused on big game. A narrow dietary niche at the top of the terrestrial food chain is inherently prone to instability, potentially contributing to extinction of the Neanderthals. However, limitations in detecting plant consumption imply that scientists are unaware of much of Neanderthal diet. My dissertation revises the role of plants in Neanderthal subsistence using dental calculus, a material that is recognised to contain food traces, as a source of dietary data. To do this I assessed how accurately calculus records diet, by testing it with a variety of techniques on a population of chimpanzees with decades of documented dietary history. Then, my dissertation examined if it is possible to explore the resilience of the Neanderthal dietary niche by assessing for changes in plant use over time. Comparing diets from different habitats, data suggests a broad range of diets on the Mediterranean rim and in the cooler areas of the Neanderthal range. Surprisingly, the study found no evidence of changes in plant dietary breadth despite variation in environments. This stability implies a deeply resilient ecological niche across their range. Show less
Chimpanzees are the only animal species that can be infected with HIV-1. Infection kinetics in both humans and chimpanzees are similar, in contrast to humans, chimpanzees do not show any signs of... Show moreChimpanzees are the only animal species that can be infected with HIV-1. Infection kinetics in both humans and chimpanzees are similar, in contrast to humans, chimpanzees do not show any signs of immunodeficiency for many years. In this thesis specific aspects of the human and chimpanzee immune system are compared to unravel the differences in cellular immune responses in relation to HIV-1 infection. Human CD4 T-cells have less CD40L expression once the viral envelope is bound to the CD4 receptor. This is also seen in chimpanzees, but this occurs at a 5 fold higher antigen level, leading to the conclusion that chimpanzees are less sensitive for immunodeficiency. Little information is known about chimpanzee NK cells. The majority of this thesis describes the differences and overlaps between human and chimpanzee NK cells, with a focus on activatory receptors. Chimpanzee NK cells show small differences in the expression of these receptors, leading to the conclusion that these cells need more triggers than ligand binding, resulting in the hypothesis that chimpanzee NK cells are in less risk of over activation, which is seen in human lymphocytes. This overactivation leads to an exhausted immune system, which is thought to be the basis for immunodeficiency. Show less
