Simon Underdown

The Neanderthals: a Social Synthesis

The Neanderthals have long fascinated archaeologists and anthropologists alike. Similarity to us coupled with clear differences has produced endless theorizing. This article reviews the background to such ideas. It examines the current lines of thought about Neanderthals and explores the validity of the conclusions. The ultimate aim is the construction of a social synthesis, a solid foundation upon which the validity of inferences regarding Neanderthal cognitive ability and behavioural complexity may be examined.

Neanderthal genomics suggests a pleistocene time frame for the first epidemiologic transition.

High quality Altai Neanderthal and Denisovan genomes are revealing which regions of archaic hominin DNA have persisted in the modern human genome. A number of these regions are associated with response to infection and immunity, with a suggestion that derived Neanderthal alleles found in modern Europeans and East Asians may be associated with autoimmunity. As such Neanderthal genomes are an independent line of evidence of which infectious diseases Neanderthals were genetically adapted to. Sympathetically, human genome adaptive introgression is an independent line of evidence of which infectious diseases were important for AMH coming in to Eurasia and interacting with Neanderthals. The Neanderthals and Denisovans present interesting cases of hominin hunter-gatherers adapted to a Eurasian rather than African infectious disease package. Independent sources of DNA-based evidence allow a re-evaluation of the first epidemiologic transition and how infectious disease affected Pleistocene hominins. By combining skeletal, archaeological and genetic evidence from modern humans and extinct Eurasian hominins, we question whether the first epidemiologic transition in Eurasia featured a new package of infectious diseases or a change in the impact of existing pathogens. Coupled with pathogen genomics, this approach supports the view that many infectious diseases are pre-Neolithic, and the list continues to expand. The transfer of pathogens between hominin populations, including the expansion of pathogens from Africa, may also have played a role in the extinction of the Neanderthals and offers an important mechanism to understand hominin-hominin interactions well back beyond the current limits for aDNA extraction from fossils alone. Am J Phys Anthropol 160:379-388, 2016.

A potential role for transmissible spongiform encephalopathies in Neanderthal extinction.

The Neanderthals were a Eurasian human species of the genus Homo that disappeared approximately 30,000 years ago. The cause or causes of their extinction continues to intrigue specialists and non-specialists alike. Here a contributory role for Transmissible Spongiform Encephalopathies (TSEs) is suggested. TSEs could have infected Neanderthal groups as a result of general cannibalistic activity and brain tissue consumption in particular. Further infection could then have taken place through continued cannibalistic activity or via shared used of infected stone tools. A modern human hunter-gatherer proxy has been developed and applied as a hypothetical model to the Neanderthals. This hypothesis suggests that the impact of TSEs on the Neanderthals could have been dramatic and have played a large part in contributing to the processes of Neanderthal extinction.

Migrating microbes: what pathogens can tell us about population movements and human evolution

Abstract Background: The biology of human migration can be observed from the co-evolutionary relationship with infectious diseases. While many pathogens are brief, unpleasant visitors to human bodies, others have the ability to become life-long human passengers. The story of a pathogen’s genetic code may, therefore, provide insight into the history of its human host. The evolution and distribution of disease in Africa is of particular interest, because of the deep history of human evolution in Africa, the presence of a variety of non-human primates, and tropical reservoirs of emerging infectious diseases. Methods: This study explores which pathogens leave traces in the archaeological record, and whether there are realistic prospects that these pathogens can be recovered from sub-Saharan African archaeological contexts. Results: Three stories are then presented of germs on a journey. The first is the story of HIV’s spread on the back of colonialism and the railway networks over the last 150 years. The second involves the spread of Schistosoma mansoni, a parasite which shares its history with the trans-Atlantic slave trade and the origins of fresh-water fishing. Finally, we discuss the tantalising hints of hominin migration and interaction found in the genome of human herpes simplex virus 2. Conclusions: Evidence from modern African pathogen genomes can provide data on human behaviour and migration in deep time and contribute to the improvement of human quality-of-life and longevity.

The Role of aDNA in Understanding the Coevolutionary Patterns of Human Sexually Transmitted Infections

Analysis of pathogen genome data sequenced from clinical and historical samples has made it possible to perform phylogenetic analyses of sexually transmitted infections on a global scale, and to estimate the diversity, distribution, and coevolutionary host relationships of these pathogens, providing insights into pathogen emergence and disease prevention. Deep-sequenced pathogen genomes from clinical studies and ancient samples yield estimates of within-host and between-host evolutionary rates and provide data on changes in pathogen genomic stability and evolutionary responses. Here we examine three groups of pathogens transmitted mainly through sexual contact between modern humans to provide insight into ancient human behavior and history with their pathogens. Exploring ancient pathogen genomic divergence and the ancient viral-host parallel evolutionary histories will help us to reconstruct the origin of present-day geographical distribution and diversity of clinical pathogen infections, and will hopefully allow us to foresee possible environmentally induced pathogen evolutionary responses. Lastly, we emphasize that ancient pathogen DNA research should be combined with modern clinical pathogen data, and be equitable and provide advantages for all researchers worldwide, e.g., through shared data.

Do patterns of covariation between human pelvis shape, stature, and head size alleviate the obstetric dilemma?

Fischer and Mitteroecker claim to have resolved the obstetric dilemma by establishing a previously unrecognized, ameliorating pattern of selective covariation between pelvis shape, stature, and head size (1). We feel that, although their results are intriguing, the authors do not fully consider the interconnecting web of factors that play important roles in complexity and the evolutionary trade-off between bipedalism and the pattern of increasing brain size in the genus Homo.

Human biology of migration

How does migration influence and shape human biology? This was the central question posed to the participants of the 57th SSHB Symposium held in December 2016 at the Aarhus Institute of Advanced Studies at the University of Aarhus in Denmark. This special issue of the Annals of Human Biology contains papers by some of those participants and several specially selected papers that help to reflect the themes and questions explored during the meeting. The papers draw from methods and approaches across the spectrum of human biology and reflect the complex and interlinked processes that not only influence human migration, but also the signals and patterns it leaves in our biological make-up. In this introduction we give a broad overview of the arguments set out in those papers. We also unpack and discuss the main ideas underlying assumptions about what migration is, how it interacts with our biology, and what this process looks like. We end by exploring how migration across time and space has shaped modern human biology and continues to influence our daily lives. Migration at its simplest is the permanent or semi-permanent movement of people to a new location. It may be permanent, temporary, recurrent or seasonal and can take place in a single generation or across several. Underlying this simple concept is a complex series of processes that interact to influence multiple levels of human biology. Migration has a deep time frame in human development and is something of a common practice by our genus (Houldcroft & Underdown, 2016; Maslin et al., 2014). Hominin dispersal within Africa was well established at least 3 million years ago with the dispersal of Australopithecus species from East Africa to Southern Africa (Clarke, 2008). Subsequently, the trend started by Homo erectus around 1.8 MYA was the first of series of migration events that saw Homo antecessor colonise the Atapeurcan mountains in southern Spain around 1.2 MYA and Homo heidelbergensis extend its range from Africa to southern Britain and the Mediterranean from around 600 KYA (Ferring et al., 2011; L opez et al., 2016; Mounier & Miraz on Lahr, 2016). Similarly, the discovery of Homo floresiensis and the Denisovans reveals a complex mosaic movement and colonisation by the genus Homo during the Pleistocene (Brown et al., 2004). While it is arguable that this movement of early human species was more akin to dispersal, the impact of human global colonisation that began around 100,000 years ago is not (L opez et al., 2016). The unparalleled expansion of the human species, in terms of both numbers and range, has created a number of unique challenges to human biology. The impact of human movement can leave a widely diverse range of biological signals ranging from eco-morphological adaption to climate, adaptive changes, genetic markers and patterns of disease resistance or susceptibility. This special issue explores patterns of past and present migration on human biology and ends with an eye to what we might expect in future.