Genomics of adaptation to climate change: finding loci involved in morphometric adaptation in parrots
Recent reports of temporal increases in avian bill size may constitute an adaptive response to climate warming because bills are integral in regulating body temperature: larger bills improve heat dissipation at the same time as limiting evaporative water loss . In particular, bill surface area in mulga (Psephotus varius) and red-rumped parrots (Psephotus haematonotus) has increased by 10% and 7% respectively since 1871. The genetic basis of these increases is unknown. However, there is mounting evidence that bill morphology is underpinned by a relatively small number of loci (e.g. the ALX1 gene in Darwin’s finches). This project aims to identify loci underlying within-species changes in bill surface area in P. varius and P. haematonotus, revealing alleles and genes with relevance to climate adaptation in birds.
The project would involve analysis of museum specimens, some of them dating back to pre-1900. Candidate loci will be identified by performing whole genome sequencing for groups of specimens falling in the top and bottom 10% of bill size range, after controlling for collection location. The student will perform DNA extractions, preparation of sequence libraries, bioinformatic analysis of sequence data, and statistical analysis of final results.
The project will identify putative functional candidate alleles and genes involved in bill size variation in birds; as bill surface area has been linked to thermoregulation and thus fitness, it will contribute to our understanding of the genetic basis of climate adaptation. This project is also a test case in applying genome-wide-association analysis to museum specimens, through integrating morphometric analysis with whole-genome sequencing. Its success will demonstrate that adaptive alleles can indeed be identified from careful, ecologically informed analyses of existing historical specimens.
This project is an Honours project being done by Keira Beattie, supervised by Kerensa McElroy (ANWC/CSIRO), Loeske Kruuk and Janet Gardner, and funded by the Centre for Biodiversity Analysis.