Mitochondrial sequences reveal a clear separation between Angolan and South African giraffe along a cryptic rift valley.
BACKGROUND
The current taxonomy of the African giraffe (Giraffa camelopardalis) is primarily based on pelage pattern and geographic distribution, and nine subspecies are currently recognized. Although genetic studies have been conducted, their resolution is low, mainly due to limited sampling. Detailed knowledge about the genetic variation and phylogeography of the South African giraffe (G. c. giraffa) and the Angolan giraffe (G. c. angolensis) is lacking. We investigate genetic variation among giraffe matrilines by increased sampling, with a focus on giraffe key areas in southern Africa.


RESULTS
The 1,562 nucleotides long mitochondrial DNA dataset (cytochrome b and partial control region) comprises 138 parsimony informative sites among 161 giraffe individuals from eight populations. We additionally included two okapis as an outgroup. The analyses of the maternally inherited sequences reveal a deep divergence between northern and southern giraffe populations in Africa, and a general pattern of distinct matrilineal clades corresponding to their geographic distribution. Divergence time estimates among giraffe populations place the deepest splits at several hundred thousand years ago.


CONCLUSIONS
Our increased sampling in southern Africa suggests that the distribution ranges of the Angolan and South African giraffe need to be redefined. Knowledge about the phylogeography and genetic variation of these two maternal lineages is crucial for the development of appropriate management strategies.
Biodiversity and Climate Research Centre (BiK-F) - Ecological Genomics & Senckenberg Gesellschaft für Naturforschung (SGN), Senckenberganlage 25, 60325, Frankfurt am Main, Germany. Friederike.Bock@senckenberg.de.
Friederike
F
Bock
Giraffe Conservation Foundation, 26 Grasmere Road, Purley, Surrey, CR8 1DU, England. julian@giraffeconservation.org.|School of Biological Earth and Environmental Studies (BEES), University of New South Wales (UNSW), Sydney, New South Wales, 2052, Australia. julian@giraffeconservation.org.
Julian
J
Fennessy
Biodiversity and Climate Research Centre (BiK-F) - Ecological Genomics & Senckenberg Gesellschaft für Naturforschung (SGN), Senckenberganlage 25, 60325, Frankfurt am Main, Germany. Tobias.Bidon@senckenberg.de.
Tobias
T
Bidon
Giraffe Conservation Foundation, 26 Grasmere Road, Purley, Surrey, CR8 1DU, England. andy@giraffeconservation.org.
Andy
A
Tutchings
Giraffe Conservation Foundation, 26 Grasmere Road, Purley, Surrey, CR8 1DU, England. andri@giraffeconservation.org.
Andri
A
Marais
Giraffe Conservation Foundation, 26 Grasmere Road, Purley, Surrey, CR8 1DU, England. deaconf@ufs.ac.za.|Department Animal, Wildlife & Grassland Science, University of Free State, Faculty of Natural and Agricultural Sciences, Bloemfontein, South Africa. deaconf@ufs.ac.za.
Francois
F
Deacon
Biodiversity and Climate Research Centre (BiK-F) - Ecological Genomics & Senckenberg Gesellschaft für Naturforschung (SGN), Senckenberganlage 25, 60325, Frankfurt am Main, Germany. Axel.Janke@senckenberg.de.|Goethe University Frankfurt, Institute for Ecology, Evolution & Diversity, Biologicum, Max-von-Laue-Straße 13, 60439, Frankfurt am Main, Germany. Axel.Janke@senckenberg.de.
Axel
A
Janke
D000353:Africa, Southern; D000810:Angola; D000818:Animals; D001483:Base Sequence; D045303:Cytochromes b / Q000235:genetics; D004272:DNA, Mitochondrial / Q000032:analysis / Q000235:genetics*; D005260:Female; D014644:Genetic Variation; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D058974:Phylogeography; D012418:Ruminants / Q000145:classification* / Q000235:genetics*
D004272:DNA, Mitochondrial; D045303:Cytochromes b