Observed patterns strengthen subspecies designation
In summary, the genetic patterns we revealed strengthen the subspecies
designation of A. marina . The generally higher level of average
genetic divergence among subspecies than structured populations, the
distinct levels of genetic diversity within each subspecies, and the
clear delineation of subspecies in a small portion of the genome
complement the diagnostic morphological differences and indicate
substantial divergence among subspecies analogous to full species. The
obvious admixture when in contact and low differentiation across the
majority of the genome indicate that the subspecies have not yet formed
full species. The recognizable trifurcate split of the designated
subspecies is coupled with gene flow events, leading to reticulate
evolution within A. marina . In short, the subspecies show
species-like patterns in some respects and population-like patterns in
others. These patterns support the idea that these taxa are intermediate
between geographical populations and full species. Hence, the subspecies
designation is reasonable and informative.