{"title":"Dissecting Factors Behind Temporal Trends in the Timing of Breeding in Two Songbird Species-Evolutionary Change or Phenotypic Plasticity?","authors":"Emma Vatka, Markku Orell, Juha Merilä","doi":"10.1086/737024","DOIUrl":null,"url":null,"abstract":"<p><p>AbstractWarming climate has led to significant phenological advances in many plant and animal populations. Whether these advances represent evolutionary responses or phenotypic plasticity remain typically unknown. Using a 53-year-long time series of individually marked Great Tits (<i>Parus major</i>) and Willow Tits (<i>Poecile montanus</i>), we investigated whether the significant breeding time advances in these species could be explained as resulting from evolutionary responses, phenotypic plasticity, or both. In the case of both species, we did not find any evidence for changes in breeding values for timing of breeding, suggesting that the observed changes do not have a genetic and, hence, evolutionary basis. In contrast, we found that annually fluctuating environmental effects explained most of the variation in first egg-laying dates, suggesting that advances in breeding time were attributable to phenotypic plasticity. We further inferred that phenotypic plasticity in response to spring temperatures can fully explain the observed advancement of Great Tit phenology over time, whereas Willow Tits have advanced their phenology much beyond what would be expected from phenotypic plasticity in response to spring temperatures. The latter observation suggests that some other yet unidentified environmental factor, uncorrelated with spring temperatures, likely explains about half of the advancement in their breeding time.</p>","PeriodicalId":50800,"journal":{"name":"American Naturalist","volume":"206 4","pages":"335-346"},"PeriodicalIF":2.7000,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"American Naturalist","FirstCategoryId":"93","ListUrlMain":"https://doi.org/10.1086/737024","RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2025/7/29 0:00:00","PubModel":"Epub","JCR":"Q2","JCRName":"ECOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
AbstractWarming climate has led to significant phenological advances in many plant and animal populations. Whether these advances represent evolutionary responses or phenotypic plasticity remain typically unknown. Using a 53-year-long time series of individually marked Great Tits (Parus major) and Willow Tits (Poecile montanus), we investigated whether the significant breeding time advances in these species could be explained as resulting from evolutionary responses, phenotypic plasticity, or both. In the case of both species, we did not find any evidence for changes in breeding values for timing of breeding, suggesting that the observed changes do not have a genetic and, hence, evolutionary basis. In contrast, we found that annually fluctuating environmental effects explained most of the variation in first egg-laying dates, suggesting that advances in breeding time were attributable to phenotypic plasticity. We further inferred that phenotypic plasticity in response to spring temperatures can fully explain the observed advancement of Great Tit phenology over time, whereas Willow Tits have advanced their phenology much beyond what would be expected from phenotypic plasticity in response to spring temperatures. The latter observation suggests that some other yet unidentified environmental factor, uncorrelated with spring temperatures, likely explains about half of the advancement in their breeding time.
期刊介绍:
Since its inception in 1867, The American Naturalist has maintained its position as one of the world''s premier peer-reviewed publications in ecology, evolution, and behavior research. Its goals are to publish articles that are of broad interest to the readership, pose new and significant problems, introduce novel subjects, develop conceptual unification, and change the way people think. AmNat emphasizes sophisticated methodologies and innovative theoretical syntheses—all in an effort to advance the knowledge of organic evolution and other broad biological principles.