Investigating environmental effects upon alternative reproductive tactic frequencies in an urban salamander
Disciplines
Biodiversity | Genetics | Genomics | Population Biology
Abstract (300 words maximum)
A major challenge in biology is understanding the mechanisms maintaining genetic and phenotypic variation. Genetically determined alternative reproductive tactics—discrete, intrasexual variation within populations—provide a unique opportunity to investigate this question. In Southern Two-lined Salamanders (Eurycea cirrigera), two male tactics are determined by a Y-linked genetic polymorphism and coexist in metro Atlanta: “searching” males have mental glands and cirri used in terrestrial courtship, while “guarding” males have enlarged jaws for mate-guarding in aquatic environments. As part of a Team Research course, we evaluated how spatial heterogeneity in environmental variables influences the frequencies of searching and guarding males. We collected environmental data from streams and tissue samples from larvae, extracted DNA, and used three qPCR assays to genotype samples from 26 streams across metro Atlanta. We then modeled how environmental variables (e.g., substrate type, stream size, microhabitat, and land cover) influence tactic frequency. We hope that our results provide insight about how urbanization influences the frequency of searching and guarding male Eurycea and, more broadly, how spatial heterogeneity supports the maintenance of genetic and phenotypic variation.
Use of AI Disclaimer
no
Academic department under which the project should be listed
CSM – Ecology, Evolution, and Organismal Biology
Primary Investigator (PI) Name
Todd Pierson
Investigating environmental effects upon alternative reproductive tactic frequencies in an urban salamander
A major challenge in biology is understanding the mechanisms maintaining genetic and phenotypic variation. Genetically determined alternative reproductive tactics—discrete, intrasexual variation within populations—provide a unique opportunity to investigate this question. In Southern Two-lined Salamanders (Eurycea cirrigera), two male tactics are determined by a Y-linked genetic polymorphism and coexist in metro Atlanta: “searching” males have mental glands and cirri used in terrestrial courtship, while “guarding” males have enlarged jaws for mate-guarding in aquatic environments. As part of a Team Research course, we evaluated how spatial heterogeneity in environmental variables influences the frequencies of searching and guarding males. We collected environmental data from streams and tissue samples from larvae, extracted DNA, and used three qPCR assays to genotype samples from 26 streams across metro Atlanta. We then modeled how environmental variables (e.g., substrate type, stream size, microhabitat, and land cover) influence tactic frequency. We hope that our results provide insight about how urbanization influences the frequency of searching and guarding male Eurycea and, more broadly, how spatial heterogeneity supports the maintenance of genetic and phenotypic variation.