VCF for neutral data set in Harpagifer bispinis along the Magellan Province

Quaternary glacial cycles shaped the current distribution of polar and
cold-temperate biotas. In the Magellan province of South America, ice
covering during the last glacial maximum radically altered the
landscape/seascape, speciation rate, and the distribution of
species. Here we studied nototheniid
fishes Harpagifer spp. along the Magellan province
reported as two nominal species: H. bispinis in
Patagonia and H. palliolatus, endemic to the
Falkland/Malvinas Islands. Previous molecular analyses
in Harpagifer showed that the genus may have recently
colonized southern South America ~ 1 million years ago. The
extensive use in systematics of molecular markers to
determine evolutionary units has been improved due to
the advances in NGS. Combining traditional DNA sequences and non-targeted
GBS-SNPs we evaluated both, the presence of effective evolutionary units
and contemporary patterns of genetic structure across the Magellan
province. DNA sequences consistently showed an absence of phylogeographic
structure, with shared dominant haplotypes between nominal species,
pointing towards the presence of a single evolutionary unit. In contrast,
SNPs identified three groups in Patagonia, two located north and south of
the Strait of Magellan, and a third well-differentiated one in the
Falkland/Malvinas Islands. Connectivity analyses using SNPs suggest
limited and asymmetric gene flow from Patagonia to the Falkland/Malvinas.
Contrasting rough- and fine-scale genetic evolutionary patterns recorded
in Harpagifer enhance the relevance in the use of
combined methodologies for species delimitation analyses. Depending on the
question to be addressed, we could discriminate among phylogeographic
structure discarding incipient speciation, and contemporary spatial
differentiation processes linked to drift-migration equilibrium models.