Research

Like in case of all other species, information on hominin population dynamics is crucial if we want to understand species’ evolution and ecology. If archaeology is not rocket science, but much harder as famous archaeologist Robert Kelly has said, reconstructing prehistoric population dynamics must be especially hard (at least in the minds of many critics). Therefore, we need multiple tools in our toolbox to make sense of these dynamics: archaeological proxies, DNA-based methods, and modelling. We have been at the forefront in developing, applying and evaluating methods to reconstruct long-term population dynamics of prehistoric humans and this continues to be one of our central research themes. In our research we have also emphasized the need to use multiple proxies and to acknowledge the limitations of different methods.

Borrowing from biogeography and macroecology, we have developed a novel approach to prehistoric population dynamics as a complement to more traditional archaeological and genetic methods. In this approach, ethnographic data and model-based climate data are applied within species distribution modelling framework to simulate changes in the range and size of prehistoric hunter-gatherers. The approach is based on the idea of hind-casting climatic niche of ethnographic hunter-gatherers to prehistoric climate conditions. This allows to infer how the distribution and abundance of past hunter-gatherers would have changed if they were mainly controlled by climatic factors. To further develop the approach and to apply it in new contexts is currently one of our focus areas.

Key publications:

Oinonen, M., Pesonen, P., Tallavaara, M., 2010. Archaeological Radiocarbon Dates for Studying the Population History in Eastern Fennoscandia. 52. https://doi.org/10.1017/S0033822200045446

Tallavaara, M., Pesonen, P., Oinonen, M., 2010. Prehistoric population history in eastern Fennoscandia. Journal of Archaeological Science 37, 251–260. https://doi.org/10.1016/j.jas.2009.09.035

Tallavaara, M., Pesonen, P., Oinonen, M., Seppä, H., 2014. The Mere Possibility of Biases Does Not Invalidate Archaeological Population Proxies – Response to Teemu Mökkönen. Fennoscandia Archaeologica 31, 135–140.

Tallavaara, M., Luoto, M., Korhonen, N., Järvinen, H., Seppä, H., 2015. Human population dynamics in Europe over the Last Glacial Maximum. Proceedings of the National Academy of Sciences 112, 8232–8237. https://doi.org/10.1073/pnas.1503784112

Tallavaara, M., Jørgensen, E.K., 2021. Why are population growth rate estimates of past and present hunter–gatherers so different? Phil. Trans. R. Soc. B 376, 20190708. https://doi.org/10.1098/rstb.2019.0708

One of the key topics in our research is the analysis of how long-term human population dynamics and behavioural patterns are related to environmental variability. We have shown that biotic and abiotic factors strongly influence hunter-gatherer distribution and abundance across space and time both in ethnographic and archaeological records. For example, in northern Europe, Holocene climate changes appears to create synchrony in the long-term hunter-gatherer population dynamics. Interestingly, in the same area, the relationship between long-term population dynamics appear to break down after the beginning of farming: despite the Late Holocene cooling and decline in productivity, human population relaunched its growth with the adoption of farming and sustained the long-term growth ever since. Recently, we have launched a collaborative project exploring the influence of climate on the presence of Early and Mid Pleistocene humans in the Nihewan Basin in China.

Drawing reliable conclusions about human–environment interaction requires that the palaeoenvironmental data really track the environmental variability relevant to the people who left behind the archaeological record. Therefore, together with out collaborators, we are continuously working on to develop model- and proxy-based datasets and methods to describe Quaternary environments relevant to past humans.

Key publications

Armstrong, E., Tallavaara, M., Hopcroft, P.O., Valdes, P.J., 2023. North African humid periods over the past 800,000 years. Nature Communications 14, 5549. https://doi.org/10.1038/s41467-023-41219-4

Jørgensen, E.K., Pesonen, P., Tallavaara, M., 2022. Climatic changes cause synchronous population dynamics and adaptive strategies among coastal hunter-gatherers in Holocene northern Europe. Quaternary Research 108, 107–122. https://doi.org/10.1017/qua.2019.86

Manninen, M.A., Tallavaara, M., Seppä, H., 2018. Human responses to early Holocene climate variability in eastern Fennoscandia. Quaternary International 465, 287–297. https://doi.org/10.1016/j.quaint.2017.08.043

Tallavaara, M., Seppä, H., 2012. Did the mid-Holocene environmental changes cause the boom and bust of hunter-gatherer population size in eastern Fennoscandia? The Holocene 22, 215–225. https://doi.org/10.1177/0959683611414937

Tallavaara, M., Manninen, M.A., Pesonen, P., Hertell, E., 2014. Radiocarbon dates and postglacial colonisation dynamics in eastern Fennoscandia, in: Riede, F., Tallavaara, M. (Eds.), Lateglacial and Postglacial Pioneers in Northern Europe, BAR International Series 2599. Archaeopress, Oxford, pp. 161–175.

Tallavaara, M., Luoto, M., Korhonen, N., Järvinen, H., Seppä, H., 2015. Human population dynamics in Europe over the Last Glacial Maximum. Proceedings of the National Academy of Sciences 112, 8232–8237. https://doi.org/10.1073/pnas.1503784112

Tallavaara, M., Eronen, J.T., Luoto, M., 2018. Productivity, biodiversity, and pathogens influence the global hunter-gatherer population density. PNAS 115, 1232–1237. https://doi.org/10.1073/pnas.1715638115

Tallavaara, M., Pesonen, P., 2020. Human ecodynamics in the north-west coast of Finland 10,000–2000 years ago. Quaternary International 549, 26–35. https://doi.org/10.1016/j.quaint.2018.06.032

Only 200,000 years ago there were at least seven human species roaming on Earth, one being our own species, Homo sapiens. Currently, however, we are the only hominin left. We have also become the dominant species on the planet. One of the most important questions in science is, how this came to be. Key element here is the human ecological and behavioural plasticity. Is adaptability and a wide ecological niche really a unique feature of H. sapiens or did they start much earlier? To what extent can we see these features among earlier species? When humans started to deviate from other mammals in terms of their niche size? Finding answers to these questions may also hint about the causes of human expansion and prevalence.

Topics related to hominin niche size are new in our group, but we have currently a lot of going on relating these topics including two major projects Prehistory of Peculiarity and Environments and Energy Use of Early Humans on the Edge (more info soon). In our recent review paper (Foister et al. 2023), we show for example that when Early Pleistocene humans expanded out of Africa, variation in the habitats occupied by these humans increased. Early Pleistocene humans (H. erectus sensu lato) out of Africa did not exclusively inhabit similar environments (such as savanna) than conspecifics in Africa.

Watch this space for more news about the topic!

Key publications

Foister, T.I.F., Žliobaitė, I., Wilson, O.E., Fortelius, M., Tallavaara, M., 2023. Homo heterogenus: Variability in early Pleistocene Homo environments. Evolutionary Anthropology: Issues, News, and Reviews 32, 373–385. https://doi.org/10.1002/evan.22005

Hunter-gatherers, and pre-industrial human populations in general, provide a rare opportunity to investigate the drivers of the distribution and abundance as well as behavioural variability of a single species along global environmental gradients. For example, we have shown that net primary productivity, biodiversity, and pathogen stress have strong effects on hunter-gatherer abundance in a global ethnographic sample. Interestingly, we also found that hunter-gatherer abundance is differently constrained between the low- and high-productivity environments: resource availability and ecosystem stability matter mostly in the low- and pathogens in the high-productivity environments. Furthermore, this pattern appears to correspond the so-called Dobzhansky–MacArthur Phenomenon about the role of biotic and abiotic constraints postulated for other species, but rarely tested with global single-species data. Thus, the resulting knowledge does not only increase our understanding of the drivers of current hunter-gatherer niches or help building better models of the past humans, but it can also provide interesting ecological information with even wider relevance.

Currently, we are exploring the biogeography of hunter-gatherer subsistence – proportions of plants, terrestrial meat, and aquatic meat in the diet. As a teaser of the forthcoming: we are able to show that the geographical variation in diet composition observed among ethnographic and prehistoric hunter-gatherers follows the same pattern as observed among other omnivorous mammals.

Key publications

Tallavaara, M., Eronen, J.T., Luoto, M., 2018. Productivity, biodiversity, and pathogens influence the global hunter-gatherer population density. PNAS 115, 1232–1237. https://doi.org/10.1073/pnas.1715638115

Tallavaara, M., Jørgensen, E.K., 2021. Why are population growth rate estimates of past and present hunter–gatherers so different? Phil. Trans. R. Soc. B 376, 20190708. https://doi.org/10.1098/rstb.2019.0708