Combined evidence reveals the origin of a rapid range expansion despite retained genetic diversity and a weak founder effect

Many species are currently experiencing range shifts in response to changing environmental conditions, but with potentially serious genetic consequences. Repeated founder events and strong genetic drift are expected to erode genetic variation at the range front, reducing adaptive potential and slowing or even halting the expansion. However, the severity of these consequences for the more common and highly mobile species undergoing environment-driven range shifts (c.f. invasions) is less clear. Here we combined historical observations of the common reed warbler (Acrocephalus scirpaceus) with contemporary movement data from ringing re-encounters and genomic (RAD-seq) data from across its European breeding range to (1) infer the origin and (2) quantify the genetic consequences of a recent and rapid northward range expansion. While there were no reductions in levels of nucleotide diversity or allelic richness, nor a signal of founder effect in the directionality index (ψ), our combined..., , # Data from: Combined evidence reveals the origin of a rapid range expansion despite retained genetic diversity and a weak founder effect

Access this dataset on Dryad, DOI: [10.5061/dryad.bcc2fqzrw](10.5061/dryad.bcc2fqzrw)

## Description of the data and file structure

This repository contains the following data used in \"Combined evidence reveals the origin of a rapid range expansion despite retained genetic diversity and a weak founder effect\" (Bergman et al. 2025, Molecular Ecology):

* Dataset of the reed warblers (*Acrocephalus scirpaceus*) ringed in Finland and re-encountered in other countries (years 1969-2023, n = 326). The data is provided by the databank of the Ringing Centre at the Finnish Museum of Natural History.
* The filtered genomic reed warbler RAD-seq datasets (DS1-4) that were used in the molecular analyses of the study, in the input formats required by each analysis they were used in. The details of these datasets can be found in the original paper and its supplem...,