Revealing hidden evolutionary capacity to cope with global change

Authors: Evatt Chirgwin, Keyne Monro, Carla M Sgró And Dustin J Marshall

Published in: Global Change Biology, volume 21, issue 9 (September 2015)

Abstract

The extent to which global change will impact the long-term persistence of species depends on their evolutionary potential to adapt to future conditions.

While the number of studies that estimate the standing levels of adaptive genetic variation in populations under predicted global change scenarios is growing all the time, few studies have considered multiple environments simultaneously and even fewer have considered evolutionary potential in multi- variate context.

Because conditions will not be constant, adaptation to climate change is fundamentally a multivariate process so viewing genetic variances and covariances over multivariate space will always be more informative than relying on bivariate genetic correlations between traits. A multivariate approach to understanding the evolutionary capacity to cope with global change is necessary to avoid misestimating adaptive genetic variation in the dimensions in which selection will act.

We assessed the evolutionary capacity of the larval stage of the marine polychaete Galeolaria caespitosa to adapt to warmer water temperatures. Galeolaria is an important habitat-forming species in Australia, and its earlier life-history stages tend to be more susceptible to stress. We used a powerful quantitative genetics design that assessed the impacts of three temperatures on subsequent survival across over 30,000 embryos across 204 unique families.

We found adaptive genetic variation in the two cooler temperatures in our study, but none in the warmest temperature. Based on these results, we would have concluded that this species has very little capacity to evolve to the warmest temperature. However, when we explored genetic variation in multivariate space, we found evidence that larval survival has the potential to evolve even in the warmest temperatures via correlated responses to selection across thermal environments.

Future studies should take a multivariate approach to estimating evolutionary capacity to cope with global change lest they misestimate a species’ true adaptive potential.

Citation

Chirgwin E, Monro K, Sgró CM, Marshall DJ (2015) Revealing hidden evolutionary capacity to cope with global change. Global Change Biology, 21: 3356–3366. PDF 230 KB doi: 10.1111/gcb.12929

 

Predicting evolutionary responses to climate change in the sea

Authors: Philip L Munday, Rober R Warner, Keyne Munro, John M Pandolfi and Dustin J Marshall

Published in: Ecology Letters, volume 16, issue 12 (December 2013)

Abstract

An increasing number of short-term experimental studies show significant effects of projected ocean warming and ocean acidification on the performance on marine organisms. Yet, it remains unclear if we can reliably predict the impact of climate change on marine populations and ecosystems, because we lack sufficient understanding of the capacity for marine organisms to adapt to rapid climate change.

In this review, we emphasise why an evolutionary perspective is crucial to understanding climate change impacts in the sea and examine the approaches that may be useful for addressing this challenge.

We first consider what the geological record and present-day analogues of future climate conditions can tell us about the potential for adaptation to climate change. We also examine evidence that phenotypic plasticity may assist marine species to persist in a rapidly changing climate. We then outline the various experimental approaches that can be used to estimate evolutionary potential, focusing on molecular tools, quantitative genetics, and experimental evolution, and we describe the benefits of combining different approaches to gain a deeper understanding of evolutionary potential.

Our goal is to provide a platform for future research addressing the evolutionary potential for marine organisms to cope with climate change.

Full paper

Munday PL, Warner RR, Munro  K, Pandolfi JM, Marshall DJ (2013) Predicting evolutionary responses to climate change in the sea. Ecology Letters,  16: 1488–1500  PDFPDF 371 KB doi:10.1111/ele.12185