She might very well turn out to be right. Yang Ze, Deputy Director of the Institute for Gerontology at Beijing Hospital, has been studying Bama for ten years. Yang has repeatedly visited the region with his team of researchers, who have conducted in-depth interviews with 212 people over 90 in order to gain information about their lifestyles, diet, and family history. Much to their surprise, they found that the main reason for the longevity in the region has to do with natural selection. The region is isolated and contains many mountains—it used to take three days to get here from beyond the hills. “Conditions were rough and there was no medical care available, so the weak died off, while those with good genes survived,” Yang explains. He doesn’t dispute the importance of favorable natural conditions, such as the presence of forests, the ions in the air, the minerals in the water, and the sunshine with comparatively low levels of UV radiation. “Nevertheless, I believe that the role played by these factors has been exaggerated,” says Yang, who then comes to the same conclusion as 99-year-old Huang Majia: “If tourists keep coming here in droves, the whole phenomenon will soon disappear.”