Genetics and Evolution
Male elands have 31 diploid chromosomes and females have 32. The male (Y) chromosome has been translocated to the short arm of an autosome. Both the X and Y replicate late; they do not match well and are variable. The chromosomes resemble those of the greater kudu (Tragelaphus strepsiceros).
Male elands and female greater kudus can produce a viable male hybrid, though it is not known if it is sterile. An accidental crossing of an east African common eland (T. o. pattersonianus') with an east African kudu (T. s. bea) occurred in the San Diego Wild Animal Park. This was believed to be due to the absence of male kudus in the herd. The hybrid produced was sterile, which was unexpected before the study. The study conformed the chromosome numbers of both the eland the kudu and the strangeness of their attached Y chromosomes. Reports state that repeated matings of male elands with domestic (Bos primigenius) and zebu cows (Bos indicus) have also produced sterile hybrids. Female elands can also act as surrogates for bongos.
The Bovidae family ancestors of the common eland evolved approximately 20 million years ago in Africa; fossils are found throughout Africa and France but the best record appears in sub-Saharan Africa. The first members of the tribe Tragelaphini appear 6 million years in the past during the late Miocene. An extinct ancestor of the common eland (Taurotragus arkelli) appears in the Pleistocene in northern Tanzania and the first T. oryx fossil appears in the Holocene in Algeria.
In 2010, a genetic study was made basing on the evolutionary history of common elands. Located in the sub-Saharan savanna biome of east and southern Africa, the study used methods like analysis of mitochondrial DNA control-region fragments from 122 individuals to learn more about various topics such as the phylogeography, genetic diversity, demographic history of the species. The conclusions strongly supported the presence of a longer-standing population in the south and a mosaic of Pleistocene refugia in the east. It is believed that today their extinction from these parts could be due to colonization. The similarity of dates obtained from more studies indicates a significant event c. 200 ka, which had brought a great change in the genetic history of the species.
Read more about this topic: Common Eland
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