How lizards survived blizzards: phylogeography of the Liolaemus lineomaculatus group (Liolaemini) reveals multiple breaks and refugia in southern Patagonia, and their concordance with other co-distributed taxa

MARÍA FLORENCIA BREITMAN; LUCIANO JAVIER ÁVILA; MICAELA PARRA; JACK WALTER SITES, JR; MARIANA MORANDO

Vancouver

Congreso; 7th World Congress of Herpetology; 2012

Patagonia  was  shaped  by  a  complex  geological  history,  including  the  Miocene  uplift  of  the  Andes, followed  by  volcanism,  marine  introgressions,  and  extreme  climatic oscillations  during  Pleistocene glaciation?deglaciation  cycles.  The  distributional patterns  and  phylogenetic  relationships  of  Patagonian animals  and  plants  were affected in  different  ways,  and  those  imprints  are  reflected  in  the  seven phylogeographic breaks  and  eight  refugia  that  have  been  proposed   from  phylogeographic  studies  of some  plant  and   rodent  clades   of   southern  Patagonia.  In  this  study  we  estimated time-calibrated phylogenetic/phylogeographic  patterns  in  lizards  of  the   Liolaemus  lineomaculatus   group,  and  related them  to  historical  Miocene-to-Pleistocene  events  of Patagonia  and  the  previously  proposed  patterns summarized  from  earlier  studies.  We  also  found  evidence  for  candidate  species,  and  quantified phenotypic differences among them. I ndividuals from51 localities were sequenced for two mitochondrial (cyt- b and 12S) and one nuclear (KIF24) gene regions. Our analyses revealed strong phylogeographic structure  among  lineages  and,  in  most  cases,  no  signal  of  population  changes through  time.  The lineomaculatus  group  is composed of three strongly supported clades (lineomaculatus, hatcheri  and kolengh+silvanae),  and  divergence  estimates  suggested  that  their  origins  may  have  been  associated with  the  oldest  known  Patagonian  glaciation  (7-5  Ma),  while  subsequent  diversification  within  the lineomaculatus clade coincided with the large Pliocene glaciations (~3.5 Ma). The lineomaculatus clade lineages  are  strongly  structured  genetically  and  geographically  and  are  interpreted  (with caveats)  as young  candidate  species  showing  various  levels  of  morphological  differentiation.  Our  findings  suggest that  some   Liolaemus   lineages  have  persisted   in situ   in  multiple  refugia  through  several  glaciationdeglaciation cycles insouthern Patagonia without demographic fluctuations. We also provide qualitative evidence of some shared phylogeographic breaks and refugia among plants, rodents, and lizards.