The Role of Temporal Heterogeneity in Shaping the Frequency of Searching and Guarding Male Eurycea wilderae Salamanders
Disciplines
Animal Sciences | Biology | Ecology and Evolutionary Biology
Abstract (300 words maximum)
Understanding how genetic and phenotypic variation are maintained across generations is a key goal in evolutionary biology. One possible mechanism is temporal heterogeneity, which includes changes ecosystems experience over time, such as weather and food availability. Another mechanism is negative frequency-dependent selection, where a trait becomes more beneficial when it is rare. Alternative reproductive tactics, different ways males of the same species reproduce, are traits influenced by these factors, and we can study them more closely by examining the frequency of each tactic in a population. Our research focuses on the population of Blue Ridge Two-lined Salamanders (Eurycea wilderae) in Highlands, North Carolina. This species exhibits two alternative reproductive tactics: searching and guarding males. Searching males look for mates in the forest on rainy nights, while guarding males stay in streams and “guard” mates. Previous research shows that the difference in phenotypes is genetic; a Y-linked genetic polymorphism determines whether a male is searching or guarding. For the past four years, we have collected data on the number of guarding and searching males by sampling salamander tail tips and extracting DNA. We then tested for a relationship between the amount of rainfall in the previous year and the percentage of each male type present in the current year’s population; we hypothesize that temporal heterogeneity impacts the fitness of each phenotype and thus the frequency of these genotypes among offspring. Because searching males seek mates on wet nights, we predict that increased rainfall during the mating season will lead to a higher frequency of searching male larvae the following year. This study will help us understand whether the genotypic frequency of each male changes over time, and which mechanisms influence the maintenance of genetic polymorphisms. The more research conducted on this topic, the better we understand how genotypic and phenotypic diversity are maintained.
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
The Role of Temporal Heterogeneity in Shaping the Frequency of Searching and Guarding Male Eurycea wilderae Salamanders
Understanding how genetic and phenotypic variation are maintained across generations is a key goal in evolutionary biology. One possible mechanism is temporal heterogeneity, which includes changes ecosystems experience over time, such as weather and food availability. Another mechanism is negative frequency-dependent selection, where a trait becomes more beneficial when it is rare. Alternative reproductive tactics, different ways males of the same species reproduce, are traits influenced by these factors, and we can study them more closely by examining the frequency of each tactic in a population. Our research focuses on the population of Blue Ridge Two-lined Salamanders (Eurycea wilderae) in Highlands, North Carolina. This species exhibits two alternative reproductive tactics: searching and guarding males. Searching males look for mates in the forest on rainy nights, while guarding males stay in streams and “guard” mates. Previous research shows that the difference in phenotypes is genetic; a Y-linked genetic polymorphism determines whether a male is searching or guarding. For the past four years, we have collected data on the number of guarding and searching males by sampling salamander tail tips and extracting DNA. We then tested for a relationship between the amount of rainfall in the previous year and the percentage of each male type present in the current year’s population; we hypothesize that temporal heterogeneity impacts the fitness of each phenotype and thus the frequency of these genotypes among offspring. Because searching males seek mates on wet nights, we predict that increased rainfall during the mating season will lead to a higher frequency of searching male larvae the following year. This study will help us understand whether the genotypic frequency of each male changes over time, and which mechanisms influence the maintenance of genetic polymorphisms. The more research conducted on this topic, the better we understand how genotypic and phenotypic diversity are maintained.