Unraveling the myotis norass: Ultraconserved-element analysis reveals introgression, cryptic diversity, and taxonomic trouble

Using sequences from 2615 UCE loci and multiple methodologies we inferred
phylogenies for the largest genetic dataset of New World Myotis to date.
The resulting phylogenetic trees were populated with short branch lengths
and widespread conflict, hallmarks consistent with rapid adaptive
radiations. The degree of conflict observed in Myotis has likely
contributed to difficulties disentangling deeper evolutionary
relationships. Unlike earlier phylogenies based on 1-2 gene sequences,
this UCE dataset places M. brandtii outside the New World clades.
Introgression testing of a small subset of our samples revealed evidence
of historical but not contemporary gene flow, suggesting that
hybridization occurs less frequently in the Neotropics than in the
Nearctic. We identified several instances of cryptic lineages within
described species as well as several instances of potential taxonomic
over-splitting. Evidence from Central and South American localities
suggests that diversity in those regions is not fully characterized. In
light of the accumulated evidence of the evolutionary complexity in Myotis
and our survey of the taxonomic implications from our phylogenies it is
apparent that the definition of species and regime of species delimitation
need to be re-evaluated for Myotis. This will require substantial
collaboration and sample sharing between geneticists and taxonomists to
build a system that is both robust and applicable in a genus as diverse as
Myotis.