TY - JOUR
T1 - Variation in intraspecific demography drives localised concordance but species-wide discordance in response to past climatic change
AU - Buckley, Sean James
AU - Brauer, Chris J.
AU - Unmack, Peter J.
AU - Hammer, Michael P.
AU - Beheregaray, Luciano B.
N1 - Funding Information:
This work was supported by an Australian Research Council Future Fellowship (FT130101068) awarded to LBB, to assess adaptation and vulnerability of Australian freshwater fishes to environmental change. SJB was supported by an Australian Government Research Training Program Scholarship.
Funding Information:
We acknowledge researchers that provided samples or participated in field expeditions, especially Mark Adams. We thank Alexander Xue for providing computational advice with the codemographic modelling. This work received logistic support from Flinders University, University of Canberra and the South Australian Museum.
Publisher Copyright:
© 2022, The Author(s).
PY - 2022/12
Y1 - 2022/12
N2 - Background: Understanding how species biology may facilitate resilience to climate change remains a critical factor in detecting and protecting species at risk of extinction. Many studies have focused on the role of particular ecological traits in driving species responses, but less so on demographic history and levels of standing genetic variation. Additionally, spatial variation in the interaction of demographic and adaptive factors may further complicate prediction of species responses to environmental change. We used environmental and genomic datasets to reconstruct the phylogeographic histories of two ecologically similar and largely co-distributed freshwater fishes, the southern (Nannoperca australis) and Yarra (N. obscura) pygmy perches, to assess the degree of concordance in their responses to Plio-Pleistocene climatic changes. We described contemporary genetic diversity, phylogenetic histories, demographic histories, and historical species distributions across both species, and statistically evaluated the degree of concordance in co-occurring populations. Results: Marked differences in contemporary genetic diversity, historical distribution changes and historical migration were observed across the species, with a distinct lack of genetic diversity and historical range expansion suggested for N. obscura. Although several co-occurring populations within a shared climatic refugium demonstrated concordant demographic histories, idiosyncratic population size changes were found at the range edges of the more spatially restricted species. Discordant responses between species were associated with low standing genetic variation in peripheral populations. This might have hindered adaptive potential, as documented in recent demographic declines and population extinctions for the two species. Conclusion: Our results highlight both the role of spatial scale in the degree of concordance in species responses to climate change, and the importance of standing genetic variation in facilitating range shifts. Even when ecological traits are similar between species, long-term genetic diversity and historical population demography may lead to discordant responses to ongoing and future climate change.
AB - Background: Understanding how species biology may facilitate resilience to climate change remains a critical factor in detecting and protecting species at risk of extinction. Many studies have focused on the role of particular ecological traits in driving species responses, but less so on demographic history and levels of standing genetic variation. Additionally, spatial variation in the interaction of demographic and adaptive factors may further complicate prediction of species responses to environmental change. We used environmental and genomic datasets to reconstruct the phylogeographic histories of two ecologically similar and largely co-distributed freshwater fishes, the southern (Nannoperca australis) and Yarra (N. obscura) pygmy perches, to assess the degree of concordance in their responses to Plio-Pleistocene climatic changes. We described contemporary genetic diversity, phylogenetic histories, demographic histories, and historical species distributions across both species, and statistically evaluated the degree of concordance in co-occurring populations. Results: Marked differences in contemporary genetic diversity, historical distribution changes and historical migration were observed across the species, with a distinct lack of genetic diversity and historical range expansion suggested for N. obscura. Although several co-occurring populations within a shared climatic refugium demonstrated concordant demographic histories, idiosyncratic population size changes were found at the range edges of the more spatially restricted species. Discordant responses between species were associated with low standing genetic variation in peripheral populations. This might have hindered adaptive potential, as documented in recent demographic declines and population extinctions for the two species. Conclusion: Our results highlight both the role of spatial scale in the degree of concordance in species responses to climate change, and the importance of standing genetic variation in facilitating range shifts. Even when ecological traits are similar between species, long-term genetic diversity and historical population demography may lead to discordant responses to ongoing and future climate change.
KW - Biogeography
KW - Coalescent analysis
KW - Comparative phylogeography
KW - Percichthyidae
KW - Temperate Australia
UR - http://www.scopus.com/inward/record.url?scp=85126798473&partnerID=8YFLogxK
U2 - 10.1186/s12862-022-01990-2
DO - 10.1186/s12862-022-01990-2
M3 - Article
C2 - 35317750
AN - SCOPUS:85126798473
SN - 1472-6785
VL - 22
SP - 1
EP - 14
JO - BMC Ecology and Evolution
JF - BMC Ecology and Evolution
IS - 1
M1 - 35
ER -