Love works in mysterious ways in China

Fans of Star Trek are familiar with the Prime Directive: Never interfere with the development of any culture.

Of course, Star Trek is fiction. But something like the Prime Directive is playing out in our time. Remote tribes in places like the deep Amazon jungle and on North Sentinel Island in the Indian Ocean have never been contacted by outsiders. It's estimated that the Sentinelese have maintained their primitive way of life for perhaps 55,000 years.

Their paternalistic - and self-appointed - guardians in the modern world say they should be left alone, otherwise their culture could be lost forever.