Integrative taxonomy (IT) is becoming a preferred approach to delimiting species boundaries by including different empirical criteria. IT methods can be divided into two types of procedures both of which use multiple kinds of evidence: step-by-step approaches test hypotheses by sequential evaluation in a hypothetic-deductive framework, while model-based procedures delimit groups based on statistical information criteria. In this study we used a step-by-step approach and a Gaussian clustering (GC) method to test species boundaries in the northernmost species of the Liolaemus montanus group. We used different methods based on mitochondrial and nuclear DNA sequence data, morphological measures and niche envelope variables. In contrast with GC, our step-by- step approach shows that one Andean population (Abra Apacheta) previously considered part of L. melanogaster, is actually nested within another clade; another Andean species, L. thomasi, is equivocally shown to be either a distinct species or conspecific with L. ortizi; and an additional Andean population (Abra Toccto) is delimited by concordance among most lines of evidence and different methods as a distinct lineage. However, one of the oldest and low-elevation populations (Nazca) is strongly delimited by all data sets and IT procedures as a new lineage distinct from any currently recognized species.
Bibliographical noteFunding Information:
We thank J. C?rdova, C. Torres (MUSM), A. Resetar (FMNH), J. Losos, J. Rosado (MCZ), F. Glaw (ZSM), L. Welton and R. Brown (KU) for loans and accessions of specimens under their care. We thank Dr. D. Edwards for advice on Gaussian clustering, and C. Ramirez, C. Salas, A. Guzman, A. Mendoza, V. Vargas, F. Huari and J. C. Cusi for assistance in the fieldwork. We also thank an anonymous reviewer, J. A. Allen and C. L. Malone for improving with their comments a previous version of this paper. Fieldwork was supported by the Waitt Foundation-National Geographic Society (award W195-11 to CA and JWS), the BYU Bean Life Science Museum (JWS), and lab work by NSF-Emerging Frontiers award (EF 1241885 to JWS), Dr. C.G. Sites to JWS, and NSF-Doctoral Dissertation Improvement Grant (award #1501187 to JWS and CA). Permits (RD N? 1280-2012-AG-DGFFS-DGEFFS, RD N? 008-2014-MINAGRI-DGFFS-DGEFFS) were issued by the Ministerio de Agricultura, Lima, Peru, and the work was approved by the BYU Institutional Animal Care and Use Committee protocol number 12001 and in accordance with US law
- Pacific lowland
- Peruvian Andes
- Species boundaries