Poster Presentation Society for Molecular Biology and Evolution Conference 2016

Population differentiation and local adaptation in the Australian house sparrow. (#526)

Samuel C. Andrew 1 , Simon C. Griffith 1 , Lee A. Rollins 2
  1. Biological Sciences, Macquarie University, North Ryde, NSW, Australia
  2. School of Life and Environmental Sciences, Deakin University, Geelong, VIC, Australia

The house sparrow (Passer domesticus) was introduced to Australia in the 1860’s by Acclimatisation societies. Over the next hundred years the species spread across all of eastern Australia from multiple introduction points. Because the house sparrow is an obligate commensal species, they have jumped from settlement to settlement creating a fragmented meta-population across the sparsely populated areas of Eastern Australia. Independent founder events and successive bottle necks as the species has jumped from one settlement to the next, has resulted in genetic population structure. We have used microsatellite data to show the genetic differentiation across the Australian distribution (26 sample populations, n = 1248). This population structure can mostly be explained by founder effects, Isolation by Distance and independent human introductions. However, the effects of selection on population differentiation have never been tested in this species across a broad climate range. Our findings relating to genetic and morphological differentiation are consistent with results on this species in North America, South America and Europe. We are expanding on this work by using a landscape genomics approach (genome wide SNP data) to identify the effects of selection on functional loci, potentially resulting from local adaptation to the varied climate conditions across the Australian meta-population. Multiple introduction events allow us to validate our results with repeated observations to compare the effects of demographic processes and selection. Ultimately we aim to identify molecular mechanisms that make this species one of the best avian climate generalists.