Analysis of differences in climate niches of the world´s mammals with respect to their phylogenetic positions
Final Report Abstract
Overall, the studies we reviewed as part of this project converged on the finding that mammals, large bodies organisms and wide-ranging organisms show little niche conservatism. These species seem to be able to adapt to varying environmental conditions. The most parsimonious explanation is that their fundamental niche is very wide and hence the realised niche (which is quantified by range maps) may shift substantially within them. For most species, climate niches were similar to other species traits and displayed a phylogenetic signal, i.e. were similar among related taxa. As there is also geographic overlap between related taxa, this does not mean that niches are conserved as such, but that they live in similar regions and only appear conserved. Without data on the historic distribution and historic climate this cannot be separated. The pattern of species richness we observe today is, in large part, the result of evolutionary processes. The rates and balance of speciation and extinction have often been invoked to explain latitudinal richness gradients, but recent studies have called such analyses into question, largely because inferring speciation rates from phylogenies is burdened with assumptions and has large uncertainties. Here we resort to species age as a proxy of speciation rates which is much less affected by the structure of deep phylogeny and hence more robust and potentially indicates whether a region is a source of species, or a sink. We found for rodents and ruminants that species-rich locations have higher skews, i.e. a higher proportion of young species, indicating that species richness begets higher speciation rates. Our project shows that although data and approaches are burdened with uncertainty, some general statements can be made. Future research project will need to address data quality issues more than is currently the case, however, in order to avoid speculation.
Publications
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Reconstructing the ancestral climate niche: a review of challenges and approaches. Ecology & Evolution
Budic L & Dormann CF
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(2012). Climatic-niche evolution and species diversification in the Cape flora, South Africa. Journal of Biogeography, 39, 2201-2211
Schnitzler, J., Dormann, C. F., Graham, C. H., Schiffers, K., & Linder, H. P.
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(2012). What’s on the horizon for macroecology? Ecography, 35, 673-683
Beck, J., Ballesteros-Mejia, L., Buchmann, C. M., Dengler, J., Fritz, S. A., Gruber, B., Hof, C., Jansen, F., Knapp, S., Kreft, H., Schneider, A.K., Winter, M. & Dormann, C.F.
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(2015) Analyses and Methodological Challenges in Explaining Past and Present Distribution and Climatic Preferences of Terrestrial Mammals. PhD Thesis, Faculty of Environment and Natural Resources, University of Freiburg
Budic L.
