01whole.pdf (1.82 MB)
Download file

Landscape genetic connectivity and sex-specific responses in a range expanding damselfly

Download (1.82 MB)
posted on 28.03.2022, 15:26 by Alexander Robert Carey
Range shifts induced by climate change have been documented in many insect taxa. The damselfly, Ischnura elegans, is undergoing a poleward range expansion in northern Europe showing local adaptation to environmental conditions at the range edge in Sweden. However,the role of neutral genetic connectivity and sex-specific responses in the range expansion process is unknown. We examine relative abundance, sex-specific landscape genetic relationships and morphological variation in I. elegans along a ~600km range expansion axis. We analysed 29 landscape resistance surfaces against genetic distances (FST and G`ST) calculated from 3,554 RAD seq-derived neutral Single Nucleotide Polymorphisms (SNPs) from 25 sites (n = 426 individuals). Resistance modelling showed cooler mean annual temperatures limited genetic connectivity linearly, with greater resistance at colder range limit sites. Relative site abundances were reduced along the sampled gradient; however,genetic diversity showed no significant change, suggesting recent colonisations. Results were consistent with female-biased dispersal, with females showing reduced temperature resistance to gene flow and a small, almost linear effect of land cover type that was not observed in males. Female, but not male, wing length also increased towards the range limit. Our findings demonstrate sex-specific morphological and landscape genetic responses during a climate-change induced range expansion.


Table of Contents

Introduction -- Materials and methods -- Results -- Discussion -- Conclusion -- Acknowledgements -- References -- Supplementary material.


Thesis by publication. Bibliography: pages 46-56

Awarding Institution

Macquarie University

Degree Type

Thesis MRes


MRes, Macquarie University, Faculty of Science and Engineering, Department of Biological Sciences

Department, Centre or School

Department of Biological Sciences

Year of Award


Principal Supervisor

Rachael Y. Dudaniec


Copyright Alexander Robert Carey 2018. Copyright disclaimer: http://mq.edu.au/library/copyright






1 online resource (69 pages) colour illustrations, colour maps

Former Identifiers

mq:71304 http://hdl.handle.net/1959.14/1272976