Acknowledgements
We thank R. Butôt for laboratory assistance, B. Wielstra for
constructive comments on earlier versions of the manuscript, and O.
Schaap and K. Vrieling for running the SNP line. JLD thanks the “Jan
Joost ter Pelkwijk fonds” for a travel grant and G. Clifton, A.
Delgado, J. López and A. Mateo for fieldwork assistance. Permission to
access genetic resources in Portugal was granted by the Instituto da
Conservação da Natureza e da Biodiversidade, Lisbon (permit no.
94263/13.11.2017).