Impact of climate and environmental changes

This project is conducted as a consortium with ISEA PAS

Princial Investigator prof. Adam Nadachowski

Biologists and ecologists are currently developing a better understanding of the mechanisms by which species and ecosystems can be impacted by climate changes. Attempts to predict the response of the animal populations and species to future climate and environmental changes can be aided by study of past analogues. The general goal of this project is to use genetic and morphological data obtained from fossil and contemporary specimens to investigate population dynamics, migrations and extinctions of three small mammal species during the Late Pleistocene and Holocene and to assess the impact of climate changes onto those events. These species namely the bank vole (Clethrionomys glareolus), the narrow-headed vole (Microtus gregalis) and the root vole (Microtus oeconomus), were selected to represent different adaptations and environmental requirements and we assume that their evolutionary histories were different. Analyses of samples from the broad temporal and geographical range will allow us to test some specific hypotheses whether, (i) the evolutionary history of bank vole populations was more constant on low latitudes and more variable on high latitudes, (ii) the Carpathian area was a high latitude refugium of the Last Glacial Maximum (LGM) for bank vole, (iii) European narrow-headed voles were distinct from Asiatic ones at the species/subspecies level, (iv) evolutionary histories of low and high latitude populations of root vole were similar, (v) populations of studied species were more affected by climate changes that took place during Younger Dryas (YD) than LGM, (vi) molecular and morphological analyses will reveal different species histories.

To achieve these goals we plan to combine analyses of mtDNA genome sequences of ca. 150 subfossil and 50 contemporary specimens of each species and to examine morphometry of occlusal surfaces of tooth of those individuals. Paleontological materials will be selected from numerous sites across Europe dated to the last 50,000 years. We will primarily choose sites with well establish stratigraphy, we also plan to obtain radiocarbon dates for ca. 60 specimens. To generate mtDNA sequences we will take advantage of target enrichment procedure and high throughput sequencing. We will use three dimensional geometric morphometrics approach to investigate fine morphological differences between individuals. The obtained mtDNA sequences will be used to reconstruct phylogenies of each species using Bayesian and Maximum Likelihood approaches. DNA sequences from individuals of a known age will be used to calibrate phylogenies and to estimate divergence times of mtDNA lineages. Spatiotemporal distribution and divergence dating of mtDNA lineages will be used to infer migrations, local extinctions and population turnovers. Specific evolutionary hypotheses, like continuity of C. glareolus populations in Carpathian area through the LGM, will be tested with Approximate Bayesian Computations approach. The revealed evolutionary histories will be confronted with global (GICC05) and local (palynology) paleoclimatic records.

The period of Late Pleistocene and transition from the last glaciation to Holocene are an example of the last major revolution of climate and biota and major reorganization of animal communities and changes in species’ distributions. There is a growing number of studies that use paleogenetic data to reconstruct ecological responses of species to those changes. Most of them, however, focuses on single species while reactions of species to changing environments depends on combination of their individual adaptations and interactions with other species occupying the same ecosystem. Moreover, still the great majority of studies focus on large mammals, while studies of small mammals, extremely important elements of every ecosystem, are rare. This proposal goes against this trend, we will use the most up to date molecular and morphological approaches to reveal evolutionary histories of three small mammal species. We believe that such approach will provide not only valuable information on species-specific responses to climate changes but will be the first step towards the community-wide analyses.