How ancient caravan trips shaped camel DNA

"The genetic diversity we have discovered, thanks to restocking from wild 'ghost' dromedary populations, is quite remarkable in the history of its domestication," says Faisal Almathen. (Credit: Cesar I. Martins/Flickr)

Long, back-and-forth journeys by caravans shaped the single-humped camel’s genetic diversity, according to new research on both ancient and modern DNA.

Single-humped Arabian camels, also called dromedaries (Camelus dromedarius), have been fundamental to the development of human societies, providing food and transport in desert countries for over 3,000 years.

The dromedary continues to be a vital resource in trade and agriculture in hot, dry areas of the world, providing transport, milk, and meat where other species would not survive.

“The dromedary has outperformed all other domesticated mammals, including the donkey, in arid environments and continues to provide essential commodities to millions of people living in marginal agro-ecological areas,” says Faisal Almathen from the department of veterinary health and animal husbandry at King Faisal University in Saudi Arabia.

The researchers collected and analyzed genetic information from a sample of 1,083 living dromedaries from 21 countries around the world. The team combined this with an examination of ancient DNA sequences from bone samples from early-domesticated dromedaries from 400-1870 CE and wild ones from 5,000-1,000 BCE to reveal an historic genetic picture of the species.

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“The genetic diversity we have discovered, thanks to restocking from wild ‘ghost’ dromedary populations, is quite remarkable in the history of its domestication,” adds Almathen. “It underlines the animal’s potential to adapt sustainably to future challenges of expanding desert areas and global climate change.”

“Our analysis of this extensive dataset actually revealed that there is very little defined population structure in modern dromedaries,” says Olivier Hanotte, professor of genetics and conservation at the University of Nottingham. “We believe this is a consequence of cross-continental back and forth movements along historic trading routes. Our results point to extensive gene flow which affects all regions except East Africa where dromedary populations have remained relatively isolated.”

The findings appear in the Proceedings of the National Academy of Sciences.

Source: University of Nottingham