Data from: Resolving the Northern Hemisphere source region for the long-distance dispersal event that gave rise to the South American endemic dung moss Tetraplodon fuegianus

Premise of the study—American bipolar plant distributions characterize
taxa at various taxonomic ranks but are most common in the bryophytes at
infraspecific and infrageneric levels. A previous study on the bipolar
disjunction in the dung moss genus Tetraplodon found that direct
long-distance dispersal from North to South in the Miocene - Pleistocene
accounted for the origin of the Southern American endemic Tetraplodon
fuegianus, congruent with other molecular studies on bipolar bryophytes.
The previous study, however, remained inconclusive regarding a specific
Northern Hemisphere source region for the trans-equatorial dispersal event
that gave rise to T. fuegianus. Methods—To estimate spatial genetic
structure and phylogeographic relationships within the bipolar lineage of
Tetraplodon, which includes T. fuegianus, we analyzed thousands of
Restriction-site Associated DNA (RADseq) loci and single nucleotide
polymorphisms using Bayesian individual assignment and maximum likelihood
and coalescent model based phylogenetic approaches. Key
results—Northwestern North America is the most likely source of the recent
ancestor to T. fuegianus. Conclusions—Tetraplodon fuegianus, which marks
the southernmost populations in the bipolar lineage of Tetraplodon, arose
following a single long-distance dispersal event involving a T. mnioides
lineage that is now rare in the Northern Hemisphere and potentially
restricted to the Pacific Northwest region of North America. Furthermore,
gene flow between sympatric lineages of Tetraplodon mnioides in the
Northern Hemisphere is limited, possibly due to high rates of selfing or
reproductive isolation.