In July, Functional Ecology published the Special Feature: A Mechanistic Understanding of Global Change Ecology. We have invited the authors of the papers to write a blogpost on their paper. In this article, Sarah Diamond expands on her paper, Contemporary climate‐driven range shifts: Putting evolution back on the table, by looking at evolving perspectives on range shifts in a changing world.
Over the history of the Earth, species range boundaries have shifted substantially, for example moving with the advancement and retreat of glaciers during the transition from the last ice age. But species are moving faster and farther than ever before as humans continue to modify the environment. Although the evolution of ranges over historical timescales has been a vigorous area of research, how much evolution can tell us about contemporary range shifts under recent climate change is an open question.
What’s in a range?
Where species live and why such incredible diversity in species ranges exists are some of the earliest fundamental research questions. The breadth of this field is similarly diverse. For example, ecological considerations of the role of species interactions in shaping range are counterbalanced by more evolutionary considerations of genetic diversity throughout the geographic range.
Drawing on both ecological and evolutionary aspects, comparative research on the relationship between range size or position (more poleward or more equatorward) and environmental tolerance has become a major research question in the field. And with recent climate change, such analyses of range and tolerance variation have become increasingly relevant, not only for basic research, but for vulnerability forecasting efforts.
Where are ranges going? Biological patterns.
Shifting geographic ranges are a major, already-visible sign of the impacts of climate change on species. The distance over which species move is not an insubstantial amount— some extreme cases, ranges have shifted hundreds of kilometers in just a few decades.
Although there is a general trend towards poleward and upslope range shifts, as species track their historical climatic niches, there is still a large amount of variation in how far species move. And further still, not all species move poleward or upslope. A sizable number of species shift equatorward, downslope, or even longitudinally. How do we explain this variation, and could we possibly forecast what future ranges will look like?
Where are ranges going? Research directions.
To understand variation in the contemporary range shift response and potentially use this information to predict future ranges, a number of research teams have turned their attention toward the role of evolution plays in the nature and magnitude of range shifts.
One area concerns the degree to which shared evolutionary history might explain variation among closely related species in their range shift responses under recent climate change. If contemporary range shift responses are very similar among closely related species, this could indicate the potential for shared underlying genetic or developmental constraints that might ultimately limit the evolution of the range shift response. At the moment, range shift responses seem quite variable among closely related species, though some taxa show substantially more possibility of constraint than others.
Another area seeing rapid growth is empirical and mathematical modeling efforts on the potential for range-limiting traits of species (for example, environmental tolerance traits) to evolve over contemporary timescales. The unifying themes with these types of studies are whether the potential for such range-limiting traits to evolve can explain variation in the range shift response with recent climate change, and relatedly, whether the evolution of range-limiting traits will be sufficient to allow future persistence. Importantly, these studies have yielded insights and conclusions that differ from approaches that do not consider evolution, reinforcing the critical nature of these evolutionary-focused analyses.
So far, it seems that we ignore evolution at our peril when it comes to understanding and predicting contemporary range shifts.
Want to know more?
For an overview of range shifts among diverse taxa, see Chen et al. 2011. Lenoir and Svenning (2015) highlight some of the exceptions to poleward and equatorward range shifts in addition to providing a broad overview of the field. And Pecl and colleagues (2017) explore the consequences of contemporary range shifts for human well-being.
On the specific topic of evolution’s role in range shift responses to recent climate change, Comte and colleagues (2014) explore the role of shared evolutionary history in stream fish range shifts; Lancaster and colleagues (2015) combine detailed monitoring with physiological tests to uncover how plasticity and evolutionary change in thermal tolerance traits are related to shifting geographic ranges in damselflies; and Bush and colleagues (2016) take empirical estimates on the evolution of thermal tolerance and use it to forecast future ranges in Drosophila.
Finally, these research themes are reviewed by Diamond (2018) as part of a recent special feature in Functional Ecology, Towards a Mechanistic Understanding of Global Change Ecology.
Bush, A., Mokany, K., Catullo, R., Hoffmann, A., Kellermann, V., Sgrò, C., … & Ferrier, S. (2016). Incorporating evolutionary adaptation in species distribution modelling reduces projected vulnerability to climate change. Ecology letters, 19(12), 1468-1478.
Chen, I. C., Hill, J. K., Ohlemüller, R., Roy, D. B., & Thomas, C. D. (2011). Rapid range shifts of species associated with high levels of climate warming. Science, 333(6045), 1024-1026.
Comte, L., Murienne, J., & Grenouillet, G. (2014). Species traits and phylogenetic conservatism of climate-induced range shifts in stream fishes. Nature communications, 5, 5023.
Diamond, S. E. (2018). Contemporary climate‐driven range shifts: putting evolution back on the table. Functional Ecology.
Lancaster, L. T., Dudaniec, R. Y., Hansson, B., & Svensson, E. I. (2015). Latitudinal shift in thermal niche breadth results from thermal release during a climate‐mediated range expansion. Journal of Biogeography, 42(10), 1953-1963.
Lenoir, J., & Svenning, J. C. (2015). Climate‐related range shifts–a global multidimensional synthesis and new research directions. Ecography, 38(1), 15-28.
Pecl, G. T., Araújo, M. B., Bell, J. D., Blanchard, J., Bonebrake, T. C., Chen, I. C., … & Falconi, L. (2017). Biodiversity redistribution under climate change: Impacts on ecosystems and human well-being. Science, 355(6332), eaai9214.