This blog post is adapted from the Oryx article “”What is in a name? Common name misuse potentially confounds the conservation of the wild camel Camelus ferus”. This post focuses on the genetic distinctions, for greater information on the topic of common naming please see the full article: https://doi.org/10.1017/S0030605322000114
The wild camel [Camelus ferus] is a separate species to the domestic Bactrian camel [Camelus bactrianus]. There is abundant scientific proof that supports this. This species distinction should be widely understood and advertised by conservation organisations as it suggests greater conservation importance for this critically endangered species.
The wild camel was first described by Przwalski in 1878 (IUCN redlist). Unknown to the western world until this point, it was presumed to be either a feral Bactrian camel or the wild animal from which the Bactrian was domesticated. This led to its initial name of Camelus bactrianus ferus.
Throughout its range in Mongolia and China the wild camel was locally thought of as separate species to the domestic camel (Hare 1997). This was due to both behavioural “wildness” and morphological differences. Morphological differences include smaller, pyramid shaped humps, smaller body, slimmer legs (Ji et al 2009) and notably in a flatter skull shape- the name for the wild camel in Mongolia translates to “flat head”.
Although in its native range of Mongolia and China, the animal was known to be different and distinct; including being referred to with different names: domestic Bactrian (Bactrianus ferus) “temee” and wild camel khavtgai (хавтгай), it took until 2009 (Ji et al and Silbermyer et al 2009) for genetic studies to agree with local knowledge and definitively proved the two species to be separate.
As early as 1999 genetic research suggested the wild camel to be distinct from the domestic Bactrian (Jianlin et al 1999), but these preliminary genetic results were not considered resolved and were taken with caution (Walzer 2006). The first reliable study to prove the wild camel to be a separate species to the domestic Bactrian was Ji et al 2009. Since then further genetic work shows high sequence divergence in both mitochondrial DNA (Ji et al 2009, Sibermyer et al 2010 and Mohandsen et al 2017) and nuclear loci (Chuluunbat et al 2014, Jirimutu et al, Wu et al 2014 and Zhang 2019)
Camels shared common ancestors with other even toed ungulates 55-60 MYA. (Jirimutu et al 2011), with camilae and Bovidae diverging 41.4mya (Mohansen 2017). During the Eocene (40 mya) the ancestors of modern camels moved out from the north American continent to Eurasia via the Bering Isthmis (Burger 2016). 15.8 mya the ancestors of the “new world” Lamini (Llama Lhama glama, alpaca Vicugna pacos , vicuna Vicugna vicugna and gunanco Lama guanicoe) and the ancestor of the “old world” camelids- Camelini, split (Mohandsen 2017 and Burger 2016).
From this split, 3 distinct species of old-world camelid evolved, these are the one humped domestic dromedary Camelus dromedaries and the two humpeddomestic Bactrian Camelus bactrianus and wild camel Camelus ferus.
Divergence between the one humped and two humped camels is estimated to be between 5 and 8 mya (Mohandsen 2017). Estimations on when the wild camel and domestic Bactrian diverged differ between maternal and paternal DNA, but range from 0.7mya (Ji et al 2008) and 1.1 mya (0.58-1.8 MYA, Mohandesan et al 2017) in mitochondrial studies and 26,999+/-2268 ya on the paternal MSY (Felkel et al 2019).
Regardless, as the domestication of the Bactrian camel occurred between 4000-6000 years ago- long after any of these divergence estimates- it has therefore been concluded that the wild camel is neither the progenitor of the domestic Bactrian, nor is it a feral version of this species, but a separate species in its own right.
The wild camel and the domestic Bactrian can be referred to as sister species (Mohandesan et al 2017), this meaning that they diverged from a single common ancestor. This divergence can be seen at both the mitochondrial (Ji et al 2009, Sibermyer et al 2010 and Mohandsen et al 2017) and at the nuclear level (Chuluunbat et al 2014, Zhang 2019). The wild camel and the domestic Bactrian camel are separate species.
In 2003 changes by the International Commission on Zoological Nomenclature ruled that the name Camelus bactrianus ferus, should be changed for the wild camel. At the time the wild camel was classed as the progenitor of the domestic Bactrian. As a “progenitor” species the ICZN named the wild species of Bactrian Camel Camelus ferus, while the domestic form retained the name Camelus bactrianus (Gentry et al. 2004). Even though extensive modern genetic research has proved the wild camel to be a separate species to the domestic Bactrian, it still retains this progenitor title.
There is now abundant scientific evidence that shows the wild camel to be a separate species to the domestic Bactrian. By continuing to use the name “Bactrian” to describe the wild camel we could be delaying opportunities for conservation of this critically endangered species. By referring to the wild camel as Bactrian we are suggesting that the two species are one and the same, either as a progenitor or as feral animal, neither of which holds conservation importance, supports local distinctions, nor is scientifically correct. Therefore it is of great importance that the Bactrian naming of the wild camel is no longer used.
You can read more about common naming distinctions for the wild camel here: https://doi.org/10.1017/S0030605322000114
References/ Further reading:
Adiya. Y, Gunin. P. D, Naranbaatar. G and Tsogtjargal. G. (2016). The Present Status and Problems in the Preservation of Ungulate Animal Populations in the Arid Zones of Mongolia. Arid Ecosystems. 6 (3), 158-168.
Almathen et al. (2016). Ancient and Modern DNA reveal dynamics of domestication and cross-continental dispersal of the dromedary. pnas. 113 (24), 6707-6712.
Burger. P. (2016). The History of Old World Camelids in Light of Molecular Genetics. Trop Animal Health Prod. 48, 903-913.
Burger P.A , Ciani E and Faye B. (2019). Old World camels in a modern world – a balancing act between conservation and genetic improvement. Animal Genetics, 1-15.
Burger. P, Silbermayr. K, Charruau. P, Lipp. L, Dulamtseren. E, Yadamsuren A and Walzer. C. Genetic Status of Wild Camels (Camelus ferus) in Mongolia. Unpublished.
Chuluunbat. B, Charruau. P, Silbermayr. K, Khorloojav. T and Burger. P. A. (2014). Genetic Diversity and Population Structure of Mongolian Domestic Bactrian Camels (Camelus bactrianus). Animal Genetics. 45, 550-558
Evdotchenko, D, Bartenschlager, Han, H, Preuss, S and Geldermann, H,. (2003). New Polymorphic Microsatellite loci for different camel species. Molecular Ecology Notes. , 431-434.
Fitak R., 2014. Assessing the demographic history of Old World camelids through whole-genome sequencing. Scientific report. http://www.esf.org/coordinating-research/research-networking-programmes/life-earth-and-environmental-sciences-lee/current-esf-research-networking-programmes-in-life-earth-and-environmental-sciences/advances-in-farm-animal-genomic-resources-genomic-resources/scientific-activities.html. Accessed on 07 March 2015
Fitak R., 2014. Assessing the demographic history of Old World camelids through whole-genome sequencing. Scientific report. http://www.esf.org/coordinating-research/research-networking-programmes/life-earth-and-environmental-sciences-lee/current-esf-research-
Felkel. S, Wallner. B, Chuluunba. B, Yadamsuren. A, Faye. B, Brem. G and Walzer C.. (2019). A First Y-Chromosomal Haplotype Network to Investigate Male- Driven Population Dynamics in Domestic and Wild Bactrian Camels. Frontiers in Genetics. 10 (423)
Gentry A, Clutton-Brock. J and Groves C.P. (2004). The naming of wild animal species and their domestic derivatives. Journal of Archaeological Science. 31, 645-651.
Han, J., et al. “Genetic differentiation between Camelus bactrianus ferus and C. bactrianus inferred from mitochondrial DNA RFLPS.” Ecology and Conservation of Wild Bactrian Camels (Camelus bactrianus ferus) Ulaanbaatar, Mongolia: Mongolian Conservation Coalition & Admon Printing (2002): 65-70.
Hare, J. (1997). The Wild Bactrian Camel Camelus bactrianus ferus in China: the need for urgent action.. Oryx. 1, 45-48.
Ji. R, Cui. P, Geng. J, Gao. H, Zhang. H, Yu. S and Meng. H. (2009). Monophyletic Origin of Domestic Bactrian Camel (Camelus bactrianus) and it’s Evolutionary Relationship with the Extant Wild Camel (Camelus bactrianus ferus). Animal Genetics.
Jianlin H, Jiexia Q, Zhenming M, Yaping Z, and Wen W. (1999). Rapid Communication: Three Unique Restriction Fragment Length Polymorphisms of EcoRI, PvuII, and ScaI Digested Mitochondrial DNA of Bactrian Camels (Camelus bactrianus ferus) in China. Journal of Animal Science. 77, 2315-2316.
Jianlin H, Mburu D, Ochieng J, Kaufmann B, ORege J. E and Hanotte O. (2000). Application of New world camelidae microsatellite primers for amplification of polymorphic loci in old world camelids. Animal Genetics. 31, 404-419.
Jirimutu et al. (2012). Genome Sequences of Wild and Domestic Bactrian Camels. Nature Communications. 1202 (3), 2-8.
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Mohandesan. E, Fitak. R. R, Corander. J, Yadamsuren. A, Chuluunbat. B, Abdelhadi. O, Raziq. A, Nagy. P, Stalder. G, Walzer. C, Faye. B and Burger. P. (2017). Mitogenome Sequencing in the Genus Camelus Reveals Evidence for Purifying Selection and Long Term Divergence between Wild and Domestic Bactrian Camels. Nature- Scientific Reports.
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Ruiz E, Mohandsen E, Fitak R.R and Burger P.A. (2015). Diagnostic single nucleotide polymorphism markers to identify hybridisation between dromedary and bactrian camels. Conservation Genetic Resources. 7, 329-332.
Silbermayr. K, Orozco-terWengel. P, Charruau. P, Enkhbileg. D, Walzer. C, Vogl. C, Schwarzenberger. F, Kaczensky. P and Burger. P.A. (2009). High Mitochondrial Differentiation Levels Between Wild and Domestic Bactrian Camels: A Basis for Rapid Detection of Maternal Hybridisation. Animal Genetics.
Silbermayr K, Tero N, Charrau P.C, Enkhbileg D, Walzer C and Burger P.A. Isolation and Characterization of Nine Microsatellite Loci in the Domestic Bactrian Camel (Camelus bactrianus) and amplification in the wild Bactrian camel (C.ferus). Molecular Ecology Resources
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Zhang. Y, Zhong Y, Hong. Y, Xue. Y, Li. D, Zhou. C and Liu. S. (2019). RAD-Seq data Advance Captive-Based Conservation of the Wild Bactrian Camel (Camelus ferus). Conservation Genetics. 20, 817-824.