Details

Autor(en) / Beteiligte

• Hinckley, Arlo
• Hawkins, Melissa T. R.
• Maldonado, Jesús E.
• Leonard, Jennifer A.

Titel

Evolutionary history and patterns of divergence in three tropical east Asian squirrels across the Isthmus of Kra

Ist Teil von

• Journal of biogeography, 2023-06, Vol.50 (6), p.1090-1102

Ort / Verlag

Oxford: Wiley Subscription Services, Inc

Erscheinungsjahr

2023

Link zum Volltext

Quelle

Wiley Online Library Journals Frontfile Complete

Beschreibungen/Notizen

• Aim Understanding the biotic and abiotic mechanisms underlying the generation and maintenance of biogeographic transitions represent long‐standing topics in evolutionary biology. The Isthmus of Kra (IOK) divides Sundaland and Indochina and constitutes a poorly characterized terrestrial biogeographic transition. Here we looked at population genetic structure of three species that are distributed across the IOK to gain insights into the drivers that have shaped this transition and regional diversification patterns. Location Tropical east Asia: Sundaland and Indochina. Taxa Callosciurus caniceps, Tamiops mcclellandii, and Dremomys rufigenis‐ornatus species complex (Mammalia: Rodentia: Sciuridae). Methods We generated complete mitogenomes and sequences of 11 nuclear intron fragments from 61 and 67 museum specimen samples, respectively. We assessed population structure by constructing Maximum Likelihood mitogenome phylogenies (IQTREE2), and nuclear marker haplowebs and conspecificity matrices (HaplowebMaker and CoMa). We estimated divergence dates through Bayesian phylogenetic inference (BEAST2) and put these results in the context of climatic and geological history. Results High levels of mitochondrial and nuclear divergence were identified across the IOK in all three squirrels. Lineage turnover was consistent with the two major mammal species distribution transitions near the Kangar‐Pattani Line and at the juncture between the Thai‐Malay peninsula and the mainland. Divergence of mitochondrial lineages across Kra was estimated in the late Pliocene/ early Pleistocene for all three taxa. Older Miocene/Pliocene divergences were estimated within Indochina in D. rufigenis‐ornatus and T. mcclellandii, which were paraphyletic. Main Conclusions Sundaic and Indochinese populations have possibly diverged in allopatric habitat refugia in or around mountains during periods of increased aridity and evergreen forest contraction. Ecological differences and/or topography might have influenced genetic differentiation during periods of rainforest expansion. Alternative hypotheses remain to be tested with more informative nuclear markers and additional geographic sampling.