Single-nucleotide polymorphisms (SNPs) were used to assess the genetic connectivity of western toad (Anaxyrus boreas) breeding populations along Interstate-90 near Snoqualmie Pass, WA. Sites north and south of the freeway were sampled during the breeding season of 2019. SNP loci were subsequently generated using the proprietary DArTseqTM (Canberra, ACT, Australia) method. A total of 15,468 SNPs were used to calculate pairwise FST values and three distinct breeding populations were identified, two north and one south of I-90. All pairwise FST values between these sites were low (0.02) but significantly different from 0. The lowest pairwise FST was between the two sites that were furthest apart (11.6 km), indicating higher levels of connectivity along than across the freeway. A de novo discriminant analysis of principal components (DAPC) confirmed this division between sites on either side of I-90. Although I-90 is the most prominent potential barrier on the landscape, the Yakima River may also be contributing to this division. An a priori DAPC was able to distinguish between all populations with enough confidence to assign toads that were randomly encountered in the summer of 2019 to their most likely population of origin and will be a useful tool in future studies.
","abstract_html":"<p>Single-nucleotide polymorphisms (SNPs) were used to assess the genetic connectivity of western toad (<em>Anaxyrus boreas</em>) breeding populations along Interstate-90 near Snoqualmie Pass, WA. Sites north and south of the freeway were sampled during the breeding season of 2019. SNP loci were subsequently generated using the proprietary DArTseq<sup>TM</sup> (Canberra, ACT, Australia) method. A total of 15,468 SNPs were used to calculate pairwise F<sub>ST</sub> values and three distinct breeding populations were identified, two north and one south of I-90. All pairwise F<sub>ST</sub> values between these sites were low (0.02) but significantly different from 0. The lowest pairwise F<sub>ST</sub> was between the two sites that were furthest apart (11.6 km), indicating higher levels of connectivity along than across the freeway. A <em>de novo </em>discriminant analysis of principal components (DAPC) confirmed this division between sites on either side of I-90. Although I-90 is the most prominent potential barrier on the landscape, the Yakima River may also be contributing to this division. An <em>a priori </em>DAPC was able to distinguish between all populations with enough confidence to assign toads that were randomly encountered in the summer of 2019 to their most likely population of origin and will be a useful tool in future studies.</p>","abstract_has_math":false,"creators":["Myers, Anneliese"],"institution":null,"degree_name":"Master of Science (MS)","degree_level":null,"degree_discipline":"Biology","degree_department":null,"school":null,"contributors":["Jason Irwin","Alison Scoville","Linda Raubeson"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2020,"date_issued":"2020-01-01T08:00:00Z","date_published":"2020-01-01T08:00:00Z","updated_at":"2026-07-24T01:37:48Z","subjects":["Amphibian","Connectivity","SNP","Wildlife Crossing Structure","I-90 Corridor","Snoqualmie Pass","Population Biology"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://digitalcommons.cwu.edu/etd/1371","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Jason Irwin","Alison Scoville","Linda Raubeson"]},{"key":"dc:creator","label":"Author","values":["Myers, Anneliese"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["2020-06-29T07:00:00Z"]},{"key":"dc:type","label":"Dc Type","values":["Text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Biology"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science (MS)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Amphibian","Connectivity","SNP","Wildlife Crossing Structure","I-90 Corridor","Snoqualmie Pass","Population Biology"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://digitalcommons.cwu.edu/etd/1371"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Single-nucleotide polymorphisms (SNPs) were used to assess the genetic connectivity of western toad (Anaxyrus boreas) breeding populations along Interstate-90 near Snoqualmie Pass, WA. Sites north and south of the freeway were sampled during the breeding season of 2019. SNP loci were subsequently generated using the proprietary DArTseqTM (Canberra, ACT, Australia) method. A total of 15,468 SNPs were used to calculate pairwise FST values and three distinct breeding populations were identified, two north and one south of I-90. All pairwise FST values between these sites were low (0.02) but significantly different from 0. The lowest pairwise FST was between the two sites that were furthest apart (11.6 km), indicating higher levels of connectivity along than across the freeway. A de novo discriminant analysis of principal components (DAPC) confirmed this division between sites on either side of I-90. Although I-90 is the most prominent potential barrier on the landscape, the Yakima River may also be contributing to this division. An a priori DAPC was able to distinguish between all populations with enough confidence to assign toads that were randomly encountered in the summer of 2019 to their most likely population of origin and will be a useful tool in future studies.
"]},{"key":"dc:title","label":"Title","values":["Toadal Isolation: Genetic Connectivity of the Western Toad (Anaxyrus boreas) along I-90 in the Snoqualmie Pass Area of Washington State"]}]}],"canonical_facts":{"dc:contributor":["Jason Irwin","Alison Scoville","Linda Raubeson"],"dc:creator":["Myers, Anneliese"],"dc:date.available":["2020-06-29T07:00:00Z"],"dc:description.abstract":["Single-nucleotide polymorphisms (SNPs) were used to assess the genetic connectivity of western toad (Anaxyrus boreas) breeding populations along Interstate-90 near Snoqualmie Pass, WA. Sites north and south of the freeway were sampled during the breeding season of 2019. SNP loci were subsequently generated using the proprietary DArTseqTM (Canberra, ACT, Australia) method. A total of 15,468 SNPs were used to calculate pairwise FST values and three distinct breeding populations were identified, two north and one south of I-90. All pairwise FST values between these sites were low (0.02) but significantly different from 0. The lowest pairwise FST was between the two sites that were furthest apart (11.6 km), indicating higher levels of connectivity along than across the freeway. A de novo discriminant analysis of principal components (DAPC) confirmed this division between sites on either side of I-90. Although I-90 is the most prominent potential barrier on the landscape, the Yakima River may also be contributing to this division. An a priori DAPC was able to distinguish between all populations with enough confidence to assign toads that were randomly encountered in the summer of 2019 to their most likely population of origin and will be a useful tool in future studies.
"],"dc:identifier":["https://digitalcommons.cwu.edu/etd/1371"],"dc:subject":["Amphibian","Connectivity","SNP","Wildlife Crossing Structure","I-90 Corridor","Snoqualmie Pass","Population Biology"],"dc:title":["Toadal Isolation: Genetic Connectivity of the Western Toad (Anaxyrus boreas) along I-90 in the Snoqualmie Pass Area of Washington State"],"dc:type":["Text"],"thesis:degree_discipline":["Biology"],"thesis:degree_name":["Master of Science (MS)"]},"updated_at":"2026-07-24T01:37:48Z"}