Thèse de doctorat en Zoologie
Soutenue en 2013
Le président du jury était Géraldine Veron.
Pas de résumé disponible.
Comparative phylogeography of bats (Mammalia, Chiroptera) from Indochina
With about 130 species, bats account for one third of mammal diversity in Indochina. However, the taxonomic status and distribution of bats within the region is still being gathered. In particular, little is known on the influences of climatic changes during the Plio-Pleistocene. In this study, bats from different parts of Indochina and several adjacent areas in Southeast Asia were collected from field surveys and museum’s collections. Most recorded specimens were sequenced for the mitochondrial cytochrome c oxidase subunit I (COI) gene. The sequences were then compared with those available in nucleotide databases in order to check our morphological identifications and to allow a preliminary assessment of phylogenetic and phylogeographic relationships. Our analyses of COI sequences have revealed that many species contain divergent lineages, whereas some others were found to be para- or polyphyletic. The results may be interpreted, alternatively, as taxonomic issues (cryptic species, synonymy and misidentification), or as human errors (DNA contamination and pseudogenes), or as particular genetic processes (mtDNA introgression, incomplete lineage sorting and female philopatry). To resolve these issues on three unrelated taxa, for which cryptic species diversity was assumed, i. E. , Murina (tube-nosed bats), Kerivoula (woolly bats) and Tylonycteris (bamboo bats), we performed additional morphological examinations and/or multiple-locus analyses. Most relationships revealed by mtDNA markers were confirmed by the nuDNA analyses, which allowed us to provide strong taxonomic or phylogeographic conclusions. However, we also detected a few discordances between independent molecular markers, indicative of particular biological processes, such interspecific hybridization and female philopatry associated to male-biased dispersal. Our molecular estimates of divergence times supported the fact that many speciation events have occurred during the Plio-Pleistocene, as a consequence of climatic and vegetation changes. We suggest that, during glacial periods, the populations of forest bats were isolated in distant forest refugia across Southeast Asia, e. G. , Sundaland, southern and northern Indochina, and that these successive periods of isolation have resulted in allopatric speciation.