Bayesian Skyline Plots disagree with range size changes based on Species Distribution Models for Holarctic birds
Eleanor F Miller1, Rhys E Green1, Andrew Balmford1
1Department of Zoology, University of Cambridge, Cambridge, UK.
Molecular Ecology
|June 21, 2021
Summary
Climate change impacted species' population size and geographic range since the Last Glacial Maximum. However, changes in population size did not correlate with range shifts, suggesting complex demographic responses.
Area of Science:
- Ecology
- Evolutionary Biology
- Paleoclimatology
Background:
- Quaternary climate oscillations significantly influenced global species distribution and demography.
- Bayesian Skyline Plots (BSPs) and Species Distribution Models (SDMs) are key methods for reconstructing past species dynamics.
Purpose of the Study:
- To contrast BSPs and SDMs by applying them to Holarctic bird species data since the Last Glacial Maximum (LGM).
- To investigate the relationship between changes in effective population size (Ne) and geographical range size.
Main Methods:
- Analysis of mitochondrial DNA sequences and distribution maps for 102 Holarctic bird species.
- Application of Bayesian Skyline Plots (BSPs) to estimate population size fluctuations.
- Utilisation of Species Distribution Models (SDMs) to reconstruct past geographical ranges.
Main Results:
- Most species showed increased effective population size (Ne) and geographical range since the LGM.
- No significant correlation was found between the magnitude of Ne changes and range size changes.
- Wetland birds exhibited a later and greater increase in Ne compared to other habitat specialists.
Conclusions:
- Interpreting BSPs and SDMs independently can be misleading due to a lack of correlation between population size and range dynamics.
- Population density changes, independent of range shifts, may explain the observed decoupling.
- Habitat-specific responses, like those of wetland birds, reflect post-LGM environmental changes.
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