The Afar Triangle is a unique tectonic formation where the Red Sea Rift, the East African Rift Valley and the Aden Range intersect. This is one of the hottest places on the planet, containing the lowest point in Africa - Lake Assal (−155 m below sea level) and the world's lowest volcano Dallol.
This area is regarded as the cradle of human evolution, since it is here that the fossil remains of the earliest hominins (such as Ardipithecus ramidus, Ardipithecus kadabba, Australopithecus anamensis and Australopithecus afarensis) were discovered. The modern fauna of this one of the most remote regions of the Earth remained practically unexplored until recently. An international team of researchers led by the Head of the Laboratory of Microevolution of Mammals, IEE RAS, Doctor of Biological Sciences Lavrenchenko L.A., has created an inventory of the rodent fauna of the Afar Triangle. Using rodents as a model group, the level of evolutionary uniqueness of the biodiversity of this region was assessed in a wide regional and continental biogeographical context.
16 species of rodents have been established in the region, four of them (Gerbillus amoenus, G. pyramidum, G. dasyurus, Graphiurus sp. D) were first found in Ethiopia, and one (Ammodillus imbellis) was “rediscovered” here more than a century after its first registration.
Comparative phylogeographic analysis showed that the Afar Triangle is part of the Somali biogeographic region, but its fauna is genetically different and includes narrow-range Afar endemics (Arvicanthis mearnsi, Acomys louisae, A. mullah, Gerbilliscus robustus R1, Gerbillus pusillus).
To a lesser extent, there are taxa evolutionarily associated with the Sahara-Sahel region and with the south of the Arabian Peninsula. Compared to the neighboring Ethiopian Highlands, Afar's rodent fauna is relatively poor. However, as in the Ethiopian highlands, the evolutionary uniqueness of the mammals of the Afar Triangle is very high and this region can also be considered as a separate center of endemism.
The work was carried out within the framework of the RFBR project no. 19-54-26003.
Original publication: Bryja J., Meheretu Y., Boratyński Z., Zeynu A., Denys C., Mulualem G., Welegerima K., Bryjová A., Kasso M., Kostin D.S., Martynov A.A., Lavrenchenko L.A., 2022: Rodents of the Afar Triangle (Ethiopia): geographical isolation causes high level of endemism. Biodiversity and Conservation, 31(2): 629-650.
Link to article: https://link.springer.com/10.1007/s10531-022-02354-4