Poster Session #1: South UC Ballroom
Resolving the Western Chipmunk Phylogeny
Presentation Type
Poster
Faculty Mentor’s Full Name
Jeffrey Good
Faculty Mentor’s Department
Division of Biological Sciences
Abstract / Artist's Statement
Speciation is the biological process by which new species arise. Hybridization occurs in nature when two distinct lineages produce hybrid offspring and exchange genes. Understanding these events is key to understanding the process of evolution and the origin of biodiversity. Western chipmunks are one of the most diverse groups of small mammals found in forest ecosystems across Western North America. The 23 described species of western chipmunks are frequently co-distributed across their ranges. While these different species often occupy the same general regions, they typically partition into specific ecological niches with very narrow zones of contact. These narrow areas of overlap provide the potential for hybridization and gene flow between species. Past studies examining this system suggest that there has been some hybridization and gene flow during the recent, rapid radiation of Western chipmunk species. However, the overall importance and frequency of hybridization between chipmunk species remains unclear. Previously, the evolutionary relationships among chipmunk species have been reconstructed using sequences from mitochondrial DNA and four nuclear genes. The full resolution of the chipmunk phylogeny rests on additional sequencing of DNA to provide a more complete picture of the relationships among species and the frequency and extent of hybridization. This project will begin to address this by generating genome-wide sequencing data using samples from 40 chipmunks of 13 species and various localities. DNA extracts from each sample were prepared for next-generation genetic sequencing. A custom exon capture experiment was then used to target nine million base pairs of the chipmunk genome for Illumina sequencing. These sequencing efforts generated data spanning thousands of genes in all 40 samples, which was used to construct an overall phylogeny for the group. These data provide the foundation for ongoing studies to resolve the chipmunk phylogeny and the history for hybridization in this system.
Category
Life Sciences
Resolving the Western Chipmunk Phylogeny
South UC Ballroom
Speciation is the biological process by which new species arise. Hybridization occurs in nature when two distinct lineages produce hybrid offspring and exchange genes. Understanding these events is key to understanding the process of evolution and the origin of biodiversity. Western chipmunks are one of the most diverse groups of small mammals found in forest ecosystems across Western North America. The 23 described species of western chipmunks are frequently co-distributed across their ranges. While these different species often occupy the same general regions, they typically partition into specific ecological niches with very narrow zones of contact. These narrow areas of overlap provide the potential for hybridization and gene flow between species. Past studies examining this system suggest that there has been some hybridization and gene flow during the recent, rapid radiation of Western chipmunk species. However, the overall importance and frequency of hybridization between chipmunk species remains unclear. Previously, the evolutionary relationships among chipmunk species have been reconstructed using sequences from mitochondrial DNA and four nuclear genes. The full resolution of the chipmunk phylogeny rests on additional sequencing of DNA to provide a more complete picture of the relationships among species and the frequency and extent of hybridization. This project will begin to address this by generating genome-wide sequencing data using samples from 40 chipmunks of 13 species and various localities. DNA extracts from each sample were prepared for next-generation genetic sequencing. A custom exon capture experiment was then used to target nine million base pairs of the chipmunk genome for Illumina sequencing. These sequencing efforts generated data spanning thousands of genes in all 40 samples, which was used to construct an overall phylogeny for the group. These data provide the foundation for ongoing studies to resolve the chipmunk phylogeny and the history for hybridization in this system.