Dissecting factors behind temporal trends in the timing of breeding in two songbird species – evolutionary change or phenotypic plasticity?

Warming 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 53 years long time-series of individually marked Great (Parus major) and Willow Tits (Poecile montanus), we investigated whether the significant breeding time advances in these species could be explained to result 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 lay 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 explai..., , , # Dissecting factors behind temporal trends in the timing of breeding in two songbird species – evolutionary change or phenotypic plasticity?

GENERAL INFORMATION
This README file was updated on 3.4.2025

A. Paper associated with this archive
Citation: Vatka, Emma; Orell, Markku; Merilä, Juha (2025) Dissecting factors behind temporal trends in the timing of breeding in two songbird species – evolutionary change or phenotypic plasticity?

B. Originators

* Emma Vatka, Ecology and Genetics Research Unit, Faculty of Science, University of Oulu, & Research Programme in Organismal and Evolutionary Biology, Faculty of Biological and Environmental Sciences, University of Helsinki
* Markku Orell, Ecology and Genetics Research Unit, Faculty of Science, University of Oulu
* Juha Merilä, Research Programme in Organismal and Evolutionary Biology, Faculty of Biological and Environmental Sciences, University of Helsinki, & Area of Ecology & Biodiversity, School of Biological Sciences, The University ...,