Data from: Differentiation in neutral genes and a candidate gene in the pied flycatcher: using biological archives to track global climate change

Global climate change is one of the major driving forces for adaptive
shifts in migration and breeding phenology and possibly impacts
demographic changes if a species fails to adapt sufficiently. In Western
Europe, pied flycatchers (Ficedula hypoleuca) have insufficiently adapted
their breeding phenology to the ongoing advance of food peaks within their
breeding area and consequently suffered local population declines. We
address the question whether this population decline led to a loss of
genetic variation, using two neutral marker sets (mitochondrial control
region and microsatellites), and one potentially selectively non-neutral
marker (avian Clock gene). We report temporal changes in genetic diversity
in extant populations and biological archives over more than a century,
using samples from sites differing in the extent of climate change.
Comparing genetic differentiation over this period revealed that only the
recent Dutch population, which underwent population declines, showed
slightly lower genetic variation than the historic Dutch population. As
that loss of variation was only moderate and not observed in all markers,
current gene flow across Western and Central European populations might
have compensated local loss of variation over the last decades. A
comparison of genetic differentiation in neutral loci versus the Clock
gene locus provided evidence for stabilizing selection. Furthermore, in
all genetic markers, we found a greater genetic differentiation in space
than in time. This pattern suggests that local adaptation or historic
processes might have a stronger effect on the population structure and
genetic variation in the pied flycatcher than recent global climate
changes.