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143906 - Genomic divergence in sympatry indicates strong reproductive barriers and cryptic species within Eucalyptus salubris.pdf (1.41 MB)

Genomic divergence in sympatry indicates strong reproductive barriers and cryptic species within Eucalyptus salubris

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journal contribution
posted on 2023-05-20, 22:44 authored by Binks, RM, Dorothy SteaneDorothy Steane, Byrne, M
Genetic studies are increasingly detecting cryptic taxa that likely represent a significant component of global biodiversity. However, cryptic taxa are often criticized because they are typically detected serendipitously and may not receive the follow-up study required to verify their geographic or evolutionary limits. Here, we follow-up a study of Eucalyptus salubris that unexpectedly detected two divergent lineages but was not sampled sufficiently to make clear interpretations. We undertook comprehensive sampling for an independent genomic analysis (3,605 SNPs) to investigate whether the two purported lineages remain discrete genetic entities or if they intergrade throughout the species’ range. We also assessed morphological and ecological traits, and sequenced chloroplast DNA. SNP results showed strong genome-wide divergence (FST = 0.252) between two discrete lineages: one dominated the north and one the southern regions of the species’ range. Within lineages, gene flow was high, with low differentiation (mean FST = 0.056) spanning hundreds of kilometers. In the central region, the lineages were interspersed but maintained their genomic distinctiveness: an indirect demonstration of reproductive isolation. Populations of the southern lineage exhibited significantly lower specific leaf area and occurred on soils with lower phosphorus relative to the northern lineage. Finally, two major chloroplast haplotypes were associated with each lineage but were shared between lineages in the central distribution. Together, these results suggest that these lineages have non-contemporary origins and that ecotypic adaptive processes strengthened their divergence more recently. We conclude that these lineages warrant taxonomic recognition as separate species and provide fascinating insight into eucalypt speciation.


Publication title

Ecology and Evolution










School of Natural Sciences


John Wiley & Sons Ltd

Place of publication

United Kingdom

Rights statement

© 2021 Commonwealth of Australia Department of Biodiversity, Conservation and Attractions, State Government of Western Australia Ecology and Evolution published by John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution 4.0 International (CC BY 4.0) License, ( which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

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Socio-economic Objectives

Other environmental management not elsewhere classified; Native forests

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