Origin and domestication of the Old World camelids (Camelini

The missing link in the history of our livestock species is the understanding of the domestication of the Old World camelids (Camelini). The genetic origin and ancestry of the Bactrian camel (C. bactrianus) and the Dromedary (C. dromedarius) are still in debate, whereas the ancestry of other major livestock species (e.g. cattle, sheep, goat, horse, etc.) has been explored in molecular evolutionary studies. This project aims to identify the genetic origin, the domestication process and the genetic relationship of Old World camelids with molecular genetic methods. Based on archaezoological evidence and results of our preparatory work we propose separate origins and independent evolution of the Bactrian camel and the Dromedary, contrary to previous assumptions of a common ancestry. We hypothesize that (i) the world`s last Wild Bactrian camel (C. ferus) populations in Mongolia and China are closely related to the ancestors of the domestic Bactrian camels and that the putative domestication centres lie in the East Asian regions of Northern China, Western Mongolia and Southern Kazakhstan, and (ii) the ancient and today extinct giant camel (C. thomasi) is closely related to, or identical with the wild ancestors of the one-humped Dromedary, which was domesticated on the Arabian Peninsula. Based on molecular evolutionary analysis of samples covering the distribution range of present Bactrian camel and Dromedary populations, and particularly the Wild Bactrian camel, the genetic origin and domestication process will be investigated. In addition, our international cooperation partners will contribute samples for the analysis of ancient DNA from the giant camel (C. thomasi), the Wild one-humped camel (Camelus sp.), and medieval Bactrian camel and Dromedary. Considering that the wild ancestors of our domestic animal species are the reservoir of genetic diversity, this project will contribute to the in-situ conservation of the world`s last Wild Bactrian camels and beyond, to the biodiversity of our livestock in the future.

The histories of camels and humans have long been intrinsically linked in environments where people would often not have survived without these remarkable animals. Now, when aridity is affecting ever more areas as a result of climatic change, camels will also become increasingly important. In this project we aimed to understand the domestication of Old World camelids (Camelini: Camelus bactrianus and Camelus dromedarius), one of the missing links in the history of our livestock species. Contrary to previous assumptions that the critically endangered wild camels in Mongolia and China are feral (domesticates gone wild), we proved that they represent a separate species Camelus ferus that split from a common ancestor with the domestic Bactrian camel between 0.5 and 1.2 million years ago. From these results we draw the conclusions that the current wild camels are only related with the worldwide domestic Bactrian camels and are not their direct ancestors. Hence, during domestication a pool of individuals genetically different from todays wild camels had been recruited for initial management and subsequent breeding. Since its domestication, the dromedary has had a key role in sustaining civilizations over history and across continents, outperforming all other domestic mammals in desert environments, including the donkey and the horse. Exploited in caravans along ancient routes connecting the Indian Ocean with the Mediterranean Sea, the ship of the desert continues providing basic commodities to millions of people inhabiting marginal agro- ecological zones. Our genetic results reveal a process of domestication leading to the survival of two ancient maternal lineages with a minimum of six founders (female dromedaries). We propose three putative domestication scenarios to explain this surprisingly high initial diversity relative to the limited distribution of the wild ancestor on the Arabian Peninsula and to the brief co-existence of wild and early-domesticated individuals. We found an extensively shared diversity in the global population of modern dromedaries that was beyond expectation. This highlights the intensive back-and-forth movements as a unique feature of the dromedary compared to other livestock. The results of this study are of general importance to the public in a context of uncertainty of agricultural production following from the impact of increasing desertification. The particular economic value of camels, the composition of their milk and the nature of their immune systems are attracting increasing interest from within the scientific and medical communities.