Intro
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 ecological and behavioural plasticity of our species. But this leads to the question of the origin of adaptability and the extent of the human ecological niche: Is adaptability and the large ecological niche really a feature of H. sapiens making us a peculiar among species, or does this peculiarity extend to the earliest human species? Did the expansion of the ecological niche take a leap forward in the Late Pleistocene, or was it a gradual development (Figure 1)? Answering these questions will also help us understand the reasons behind the peculiarity of our species.
In this multidisciplinary project, our aim is to combine the methods and data of archeology, biogeography and climate modeling and to find out how the human ecological niche has changed during the Pleistocene. We focus primarily on changes in the size of the human climate niche (Figure 1). In addition, we will investigate at which point humans start to differentiate themselves from other mammals in terms of the size of the size of the ecological niche.
Main questions
In this study, we will answer the following questions:
How much of the available space delimited by climate variables has been covered by the human climate niche?
Methods overview
To be able to answer the question about the human ecological niche and changes in its size, we will combine data on the distribution of human species and cultures with the model-based climate data. We extract the values of climate variables (e.g., temperature and precipitation) for archaeological and fossil sites that are dated or associated with a specific human species from contemporaneous climate layers produced by climate model. The joint distributions of these values define the size of the climatic niche in one- or multi-dimensional climatic space (Figure 2). We calculate the size of the niche with area or volume measures based on alpha shapes of a two- or three-dimensional set of points. To calculate the multidimensional hypervolume, we will use specially developed statistical tools. Using species distribution modelling approach, we will also look at which climatic factors have most strongly determined human distribution during the Pleistocene.
Publications, so far:
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