Periodic Reporting for period 1 - RESOURCEFUL (Modelling the impact of resource competition, human expansion and climate on extinction)
Reporting period: 2021-05-01 to 2024-04-30
The relative roles of humans and climate on the extinction of Pleistocene megafauna is still unclear for many species. At the end of the last ice age, severe climatic changes occurred around the same time as an increase in human occupation and activity, which complicates the discussion. Furthermore, behavioural characteristics of a species can play a key role in the process of extinction and how vulnerable a species is. Species that rely on geographically fixed resources can be particularly at risk: if through either climatic or human impacts these resources become lost or inaccessible, it can have a profound impact on the survival of the species. In order to fully understand the relative impacts of humans, climate and behaviour, we need cutting-edge methods from multiple scientific fields: ancient DNA, genomics, climate science and theoretical population modelling.
This MSCA used these tools to investigate the population dynamics of the extinct cave bear (Ursus spelaeus species complex). Cave bears were large herbivorous bears that lived in mountainous areas in Europe and western Asia. Cave bears used caves to hibernate, and previous research has suggested that, at least for some populations, these bears consistently returned to their birth cave for hibernation over many generations. If through human actions or climatic changes these caves become inaccessible, this could have been detrimental for local populations, and in turn for the species as a whole. Using palaeogenomics and population modelling, we reconstructed long-term population dynamics of this iconic Pleistocene species and gained an understanding of which particular factor (humans, climate or access to caves) has played the most critical role in the extinction process of the cave bear 25,000 years ago.
As an extinct species, cave bear represent a case where the species failed to adapt to the environmental and ecological pressures they faced, resulting in extinction. A more detailed understanding of that process will help formulate strategies to help avoid the same outcome for currently threatened species.
This MSCA used these tools to investigate the population dynamics of the extinct cave bear (Ursus spelaeus species complex). Cave bears were large herbivorous bears that lived in mountainous areas in Europe and western Asia. Cave bears used caves to hibernate, and previous research has suggested that, at least for some populations, these bears consistently returned to their birth cave for hibernation over many generations. If through human actions or climatic changes these caves become inaccessible, this could have been detrimental for local populations, and in turn for the species as a whole. Using palaeogenomics and population modelling, we reconstructed long-term population dynamics of this iconic Pleistocene species and gained an understanding of which particular factor (humans, climate or access to caves) has played the most critical role in the extinction process of the cave bear 25,000 years ago.
As an extinct species, cave bear represent a case where the species failed to adapt to the environmental and ecological pressures they faced, resulting in extinction. A more detailed understanding of that process will help formulate strategies to help avoid the same outcome for currently threatened species.
The first stage in this project involved assembling a database of all accurately dated cave bear remains, as well as curating all dates for their reliability and provenance, resulting in 311 records. By combining this data together with palaeoclimatic reconstructions, a species distribution model was then created that can predict the climate suitability for specific time intervals and specific geographic regions. This climate suitability score can be interpreted as the likelihood that cave bears could have lived in the region.
The second stage of the project focussed on retrieving palaeogenomic data from cave bear bones, which when combined with published and unpublished datasets resulted in one of the largest genomic dataset for any extinct species to date (over 30 genomes). Analysing this dataset, however, requires highly specialised computational techniques, due to the degraded nature of the DNA. In this MSCA, I worked together with the host group to develop new pipelines to analyse ancient DNA, as well as improve existing ones.
The final stage of the project will be to combine the species distribution model and palaeogenomic data into a state-of-the-art population spatial modelling framework developed by the host, Andrea Manica. As the MSCA fellow was successful in being appointed as a permanent principal investigator (Lecturer in Zoology at Bangor University), the results for this project are still forthcoming at this time.
The second stage of the project focussed on retrieving palaeogenomic data from cave bear bones, which when combined with published and unpublished datasets resulted in one of the largest genomic dataset for any extinct species to date (over 30 genomes). Analysing this dataset, however, requires highly specialised computational techniques, due to the degraded nature of the DNA. In this MSCA, I worked together with the host group to develop new pipelines to analyse ancient DNA, as well as improve existing ones.
The final stage of the project will be to combine the species distribution model and palaeogenomic data into a state-of-the-art population spatial modelling framework developed by the host, Andrea Manica. As the MSCA fellow was successful in being appointed as a permanent principal investigator (Lecturer in Zoology at Bangor University), the results for this project are still forthcoming at this time.
This project is expected to result in a deeper understanding of the extinction of cave bears, and what the relative roles are of human activities, climate change and access to geographically fixed resources. These are impacts that are extremely pressing for wildlife populations today. The interdisciplinary nature of this project has allowed for the development of a method that can model all three of these factors and qualify their relative impact. This work can be used as a springboard to help formulate conservation strategies for animals that are currently at risk from extinction, as it increases our understanding of how and why species go extinct. Maintaining biodiversity and protecting species is important for society in a variety of different ways, including cultural, social and economical.