The Extinct Blue Antelope and the Living Oryx, Phylogeny and Demography of the Tribe Hippotragini
Tue, 13/03/2018 - 18:30
SA Astronomical Observatory auditorium
The advancements in the field of ancient DNA have greatly improved our possibilities to research population dynamics and gene flow through time.
The antelope tribe Hippotragini is restricted to Africa, except for one in Arabia. Ecological preferences divide the tribe into the desert loving, arid adapted Addax/Oryx clade and the water-dependent savannah and woodland Hippotragus clade. This contrasting ecology and the wide Afro-Arabian distribution make the Hippotragini an excellent system for investigating the impact of Pleistocene climatic changes on species ranges, population dynamics, and evolution. We use historical as well as modern DNA to reconstruct and compare dated phylogenies, phylogeographic structure and genetic diversity through time.
The now extinct blue antelope (Hippotragus leucophaeus) was endemic to South Africa until its extinction about 200 years ago. It is still debated whether its extinction was caused by an already non-viable population size or by hunting by European settlers. In addition, it was proposed that the blue antelope was an east-west migrating species which suffered from population fragmentation by climatic changes at the onset of the Holocene. We use ancient and historical samples to investigate these questions.
Since the extinction of the blue antelope more species of the tribe have come close to extinction: scimitar horned oryx (Oryx dammah) and Arabian oryx (Oryx leucoryx) have gone extinct in the wild and the status of the addax (Addax nasomaculatus) is unclear. It is listed as critically endangered because of severe population fragmentation and less then 100 individuals remaining in the wild. For such taxa, examining their original population structure using extant wild populations is no longer an option. However, museum specimens and the fossil record of this clade provide a chance to reconstruct these.