Chinese archaeologists are studying the DNA samples extracted from the bones of horses unearthed from ancient sites to probe the origin of domestic horses in China.

It's still a mystery to archaeologists when and where horses were first tamed in China, said Cai Dawei, a researcher with the center of archaeological research for China's border area under the Jilin University in northwest China.

The DNA research will offer valuable clues on the study of migration, spread and domestication of horses, Cai said.

A large number of remains of domestic horses and carriages have been found in the relic sites dating back to the late Shang Dynasty (1600 BC-1100 BC) in China.

Many bones of horses who were sacrificed were discovered in the sites of the late Shang Dynasty, such as the Yin Ruins in Central China's Henan Province, the Laoniupo site in Xi'an, capital of northwest China's Shaanxi Province and the Qianzhangda site in east China's Shandong Province.

"However, horses earlier than the late Shang Dynasty were seldom found in China. And it's difficult for archaeologists to determine whether the few remains of horses earlier than the Shang Dynasty belong to domestic horses or wild ones," Cai said.

"The lack of evidence at the early period of domestication of horses and the 'sudden emergence' of tamed horses in the late Shang Dynasty makes the history of horses in China very confusing," said Cai.

In order to probe the origin of China's domestic horses, Cai's center has began the study of the DNA samples extracted from horse remains in Yin Ruins and the ancient city of Zhenghan in Henan Province, as well as the archaeological sites in northwest China's Ningxia and north China's Inner Mongolia.

The domestication of horses had a great influence on the development of human civilization. The horses not only provided human beings with meat and milk, but also were used for transportation and war.

An increasing number of remains of horses have been found in archaeological sites dating back to 4,000 BC in Eurasia and the Siberian grassland in the past few years. However, archaeologists are still not clear whether the domestication of horses originated in one region and then spread to other places, or the wild horses were tamed in different regions separately.

(Xinhua News Agency April 3, 2006)