Resolving the Northern Hemisphere source population that gave rise to the South American endemic moss Tetraplodon fuegianus
A previous study (Lewis et al 2014) estimated that a direct long-distance dispersal from the Northern to the Southern Hemisphere was responsible for the current distribution, which would likely have happened during the Miocene–Pleistocene. However, the specific location of the Northern Hemisphere population which was the source of T. fuegianus remained unclear. Improved knowledge on the source population could be informative of the likely mechanism (biotic or abiotic vectors) behind the distribution event that gave rise to the species in the Southern Hemisphere - a result both informative for T. fuegianus as well as to the origin of bipolar species in general.
Using restriction-site-associated DNA (RADseq) combined with Bayesian and maximum likelihood phylogenetic approaches we studied the spatial genetic structure and phylogeographic relationships within the bipolar lineage of the genus, includes T. fuegianus. These analyses revealed that the source population of T. fuegianus is likely located in northwestern North America. The study showed that the species likely originated from a single long-distance dispersal event from a population, that is now rare and potentially restricted to the Pacific Northwest of North America.
Lewis, L. R., Biersma, E. M., Carey, S. B., Holsinger, K., McDaniel, S. F., Rozzi, R., & Goffinet, B. (2017). Resolving the northern hemisphere source region for the long-distance dispersal event that gave rise to the South American endemic dung moss Tetraplodon fuegianus. American Journal of Botany. 104(11), 1651-1659.
Lewis, L. R., Rozzi, R., & Goffinet, B. (2014). Direct long‐distance dispersal shapes a New World amphitropical disjunction in the dispersal‐limited dung moss Tetraplodon (Bryopsida: Splachnaceae). Journal of biogeography, 41(12), 2385-2395.
Hi! I am Elise Biersma, an evolutionary biologist studying polar plants and microbes.