Modern breeding reduced horse diversity within centuries: study

The horse was one of the last animals that was domesticated by humans, long after dogs, cattle and pigs. (File/AFP)
Updated 03 May 2019
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Modern breeding reduced horse diversity within centuries: study

  • The study found a staggering loss of genetic diversity in the past 200 to 300 years that accompanied modern breeding practices
  • “What we picture as a horse today and what we picture as a horse from a thousand years ago or two thousand years ago was likely actually very different,” a researcher said

WASHINGTON: The horses that galloped the earth just a thousand years ago probably looked very different from their modern descendants, researchers said Thursday after compiling the most complete genetic history of any non-human species.
But the biggest surprise of the vast study, which involved an international team of 121 scientists and was published Thursday in the journal Cell, was the staggering loss of genetic diversity in the past 200 to 300 years that accompanied modern breeding practices.
The horse was one of the last animals that was domesticated by humans, long after dogs, cattle and pigs.
But around 5,500 years ago, people began to ride, milk and lock horses in pens — and things would never be the same between the two species.
“The horse has had a profound effect on human history,” said Ludovic Orlando, a research director with CNRS and the University of Toulouse, who coordinated the study.
Thanks to the horse, “we were able to go faster, further, and to conquer new territories. We went to war differently. We were able to plow fields and do agriculture,” he said.
“The horse of Alexander the Great was so remarkable that we know his name, Bucephalus.”
But scientists still don’t know the answer to a key question: what was the ancestor of the current domestic horse?
To this end, the team analyzed the genomes of 278 specimens (mostly horses but also donkeys and mules discovered inadvertently), mostly from the past 5,000 years, across Europe and Asia.
“This is the largest register of ancient genomes ever collected for a non-human species,” said Orlando.
Ancient genetics research saw a major technological leap in 2010 that allowed the team, working in a Toulouse laboratory, to extract and analyze DNA from bones that was not accessible before.
This led to a number of surprising discoveries: for one, an ancient line of horses were present in Iberia until at least 4,000 years ago — before mysteriously disappearing completely.
On the other end of the Eurasian landmass, another lineage of horses roaming Siberia also completely disappeared around the third millennium BCE.
“They are a sort of horse equivalent of what Neanderthals are to modern humans,” Orlando said.
Today there remain but two lineages: the domestic horse and Przewalski’s horse, also called the Mongolian wild horse.
They most likely originated in Central Asia, but this is only a hypothesis: to date, no genetic ancestor has been found.
Scientists say they are struck by the speed with which the genetic diversity of horses collapsed in the last two to three centuries, after remaining constant for the previous 4,000 years of domestication.
The 16th and 17th centuries saw the emergence of the concept of “pure” breeds.
“All the current breeds, from the Shetland pony to the Thoroughbred, were made then,” said Orlando, with traits such as speed over short distances probably favored.
Another major shift occurred between the 7th and 9th centuries, during the Arab-Muslim expansion. The invaders brought with them an oriental horse, descended from the Persian empire of the Sassanids.
A more elegant animal with a finer silhouette, this horse mixed with those that were predominant in Europe at the time, while their ancestors, those mounted by the Romans and Gauls, are today confined to two regions: Iceland and the British Isles, where they were taken by the Vikings.
“What we picture as a horse today and what we picture as a horse from a thousand years ago or two thousand years ago was likely actually very different,” said Orlando — who says his next goal, with the more than 30 other universities involved in the project, is to find out which human culture first domesticated our equine friends.
“Horse domestication is central to human history, and in 2019, we still don’t understand where it started. That’s mind-blowing.”


Rwanda’s rhino population grows, tourists expected to increase

Updated 25 June 2019
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Rwanda’s rhino population grows, tourists expected to increase

  • There are only about 1,000 black rhinos left in the wild, Jes Gruner, the Akagera National Park manager, said
  • In 2017 tourism earned Rwanda $437 million

KIGALI: Rhino keepers who successfully delivered five endangered black rhinos to Rwanda spent months hugging and coddling them inside their transport boxes to prepare them for the journey, a rhino handler said as the animals were freed on Monday.
The two male and three female eastern black rhinoceroses were flown from Safari Park Dour Kralove zoo in the Czech Republic, where they had been getting to know each other after arriving from separate European parks.
“The preparation process took several months. It started in autumn last year when two animals were brought here from Denmark and England. They started to bond, which always takes weeks because black rhinos are very alert and nervous animals,” said rhino handler Jaromir Sejnoha from the Dvur Kralove Safari Park.
“In the final phase (of preparations) the rhino is trained to stay inside the box for several minutes. We feed them and hug them in there, so they aren’t scared of the box and become accustomed to it, and so on the day of transportation they don’t get nervous and the whole transportation goes smoothly.”
There are only about 1,000 black rhinos left in the wild, Jes Gruner, the Akagera National Park manager, said. The new arrivals mean Rwanda is home to 25 of them.
Tourism is a key foreign exchange earner in the East African nation, home to mountain gorillas and the so-called “Big Five” African game animals — lions, rhinos, elephants, buffalo, and leopard.
“Every year our tourism numbers are going up and bringing these rhinos I am sure will help,” Gruner said.
The park received 44,000 visitors who generated over $2 million last year, Gruner said.
In 2017 tourism earned Rwanda $437 million. Clare Akamanzi, chief executive of the Rwanda Development Board, said 2018 numbers were not yet ready due to a change of methodology.
The push for tourist dollars in not without controversy. The government’s 2018 deal to pay British football club Arsenal £30 million ($38 million) to have “Visit Rwanda” emblazoned on the team’s jersey was criticized by politicians in some donor nations who questioned whether it was a good use of money by a government still heavily dependent on foreign aid.