Virus links Japanese to Chile's ancient mummies

SCIENTISTS HAVE established a direct link between today's inhabitants of Japan and ancient South American Indians by studying the DNA of mummies recovered from the Atacama Desert in Chile.

Researchers found a virus embedded in the genetic material of the mummified bodies identical to a virus that infects modern Japanese people. The findings show that the Aids-like virus, HTLV-1 (human T-cell leukaemia virus type- 1), must have infected the Asiatic ancestors of the ancient Amerindians who migrated to the Americas across the Bering Straits landbridge more than 20,000 years ago.

Kazuo Tajima and colleagues from the Aichi Cancer Centre Research Institute in Nagoya, Japan, found fragments of the virus in 1,500-year-old mummies recovered from the Chilean desert, the driest place on Earth. In a study published in the journal Nature Medicine, the scientists showed the range of genetic variation seen in the viruses extracted from 104 mummies closely match the viruses infecting modern Japanese.

The findings provide firm evidence to support the theory of an Asian invasion and colonisation of South America long before it was conquered by the Spanish. The researchers suggest that studying fragments of retrovirus, which like the Aids virus becomes embedded in human DNA, could help archaeologists to understand the population movements that resulted in different parts of the world being colonised. They can survive for many years in teeth and bone

"Analysis of these ancient viral sequences could be a useful tool for studying the history of human retroviral infection, as well as human prehistoric migration," they say.