Mitochondrial DNA reveals two highly divergent genetic lineages in the African buffalo (Syncerus caffer)
Until today, only few studies have concentrated on the phylogeography of the big African mammals at a continental scale, mostly based on small sample sizes. Thus, the consequences of past fragmentation effects on the genetic diversity remain poorly studied. Nevertheless, the available data on large savannah mammals tend to indicate the existence of a general phylogeographic pattern, structured in three main geographic regions: West, East and South Africa (f.ex. in kob (Kobus kob), giraffe (Giraffa camelopardalis), and warthog (Phacochoerus africanus)). We thus tried to determine in which measure the phylogeographic pattern of the African buffalo corresponds to that of the other species of African mammals studied until now. 776 samples from Western, Central, Eastern and Southern Africa, including samples of the four recognized subspecies defi ned via morphological characteristics, were used and sequenced for the D-Loop (mtDNA). An important phylogeographic structure was revealed, showing a clear separation between the individuals from South-East and Central-West Africa. This separation seems to be directly correlated to the presence of the Rift valley. Furthermore, our analyses indicate that these two lineages differentiated during the Pleistocene, which is coherent with previous studies of other African species. In conclusion, these results support the existence of only two subspecies: S. c. caffer and S. c. nanus (including S. c. brachyceros and S. c. aequinoctialis), which has important consequences for the development of conservation strategies for this species. (Texte intégral)
| Summary: | Until today, only few studies have concentrated on the phylogeography of the big African mammals at a continental scale, mostly based on small sample sizes. Thus, the consequences of past fragmentation effects on the genetic diversity remain poorly studied. Nevertheless, the available data on large savannah mammals tend to indicate the existence of a general phylogeographic pattern, structured in three main geographic regions: West, East and South Africa (f.ex. in kob (Kobus kob), giraffe (Giraffa camelopardalis), and warthog (Phacochoerus africanus)). We thus tried to determine in which measure the phylogeographic pattern of the African buffalo corresponds to that of the other species of African mammals studied until now. 776 samples from Western, Central, Eastern and Southern Africa, including samples of the four recognized subspecies defi ned via morphological characteristics, were used and sequenced for the D-Loop (mtDNA). An important phylogeographic structure was revealed, showing a clear separation between the individuals from South-East and Central-West Africa. This separation seems to be directly correlated to the presence of the Rift valley. Furthermore, our analyses indicate that these two lineages differentiated during the Pleistocene, which is coherent with previous studies of other African species. In conclusion, these results support the existence of only two subspecies: S. c. caffer and S. c. nanus (including S. c. brachyceros and S. c. aequinoctialis), which has important consequences for the development of conservation strategies for this species. (Texte intégral) |
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