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Exploring adaptation in the introduced house sparrow to Australian climates and environments

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posted on 28.03.2022, 12:17 authored by Samuel Charles Andrew
Invasive species have always been excellent models for understanding local adaptation through their colonization of new and varied environments. The house sparrow (Passer domesticus) has been a key model invasive species around the world and in this thesis, I have expanded this research to consider the Australian population across the current distribution over eastern Australia. Given that we believe most sparrows were introduced to Australia from England in the 1860’s they have colonized temperate biomes that are like their home range and very different climates in the tropical and arid biomes. I have found that genetic differentiation across this region is relatively strong, and this population structure over a range of climates can allow independent populations to adapt to local climates, over the past 150 years. In line with this idea I have found evidence of significant differentiation in morphology across climatic gradients, in this species. In another passerine species, I demonstrated that this is likely largely explained by phenotypic plasticity. Additionally, using genomic SNP data and genome scan methods I explored links between differentiation in allele frequencies and climatic variation across populations. These models found many significant outlier loci, some of which were linked to genes on the reference genome relating to traits important to local adaptation, such as thermal tolerance, immune function and morphology. In addition to exploring climate as a selective force I consider the effects of heavy metal pollution on urban sparrow populations and found outlier genes that could be relevant to responding to lead contamination. These functional loci provide targets for future research describing the mechanisms behind local adaptation. Understanding how species adapt to different environmental conditions through both phenotypic plasticity and selection will be important for predicting the response of wildlife to the rapid changes in habitat and climate caused by humans -- Abstract.

History

Table of Contents

Chapter One. General introduction -- Chapter Two. Inaccuracies in the history of a well-known introduction: a case study of the Australian House Sparrow (Passer domesticus) -- Chapter Three. Clinal variation in house sparrow body size is better explained by summer maximum temperatures during development, than cold winter temperatures -- Chapter Four. Higher temperatures during development constrain body size in the zebra finch in the wild and under experimental conditions in the laboratory -- Chapter Five. The genetic structure of the introduced house sparrow populations in Australia and New Zealand is consistent with historical descriptions -- Chapter Six. Signatures of genetic adaptation to extremely varied Australian environments in introduced European house sparrows -- Chapter Seven. Living in a heavy metal environment: Evidence for selection in the house sparrow to varied urban environments contaminated with trace elements -- Chapter Eight. General discussion.

Notes

Bibliography: pages 224-231 Thesis by publication.

Awarding Institution

Macquarie University

Degree Type

Thesis PhD

Degree

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

Department, Centre or School

Department of Biological Sciences

Year of Award

2017

Principal Supervisor

Simon C. Griffith

Additional Supervisor 1

Lee Ann Rollins

Additional Supervisor 2

Henrik Jensen

Rights

Copyright Samuel C. Andrew 2017. Copyright disclaimer: http://mq.edu.au/library/copyright

Language

English

Extent

1 online resource (vii, 236 pages)

Former Identifiers

mq:70287 http://hdl.handle.net/1959.14/1262199