Dramatic photographs ofpreviously unfound Amazon Indians have highlighted theprecariousness of the few remaining "lost" tribes and thedangers they face from contact with outsiders. The bow-and-arrow wielding Indians in the pictures releasedon Thursday are likely the remnants of a larger tribe who wereforced deeper into the forest by encroaching settlement,experts said. Rather than being "lost", they have likely had plenty ofcontact with other indigenous groups over the years, saidThomas Lovejoy, an Amazon expert who is president of The HeinzCenter in Washington. "I think there is an ethical question whether you can inthe end keep them from any contact and I think...