As I noted elsewhere in this thread: read David Reich's Who We Are and How We Got Here. To quote: > The Han Chinese are truly a large population. They have bee

As I noted elsewhere in this thread: read David Reich's Who We Are and How We Got Here. To quote: > The Han Chinese are truly a large population. They have been mixing freely for thousands of years. In contrast, there are few if any Indian groups that are demographically very large, and the degree of genetic differentiation among Indian jati groups living side by side in the same village is typically two to three times higher than the genetic differentiation between northern and southern Europeans. The truth is that India is composed of a large number of small populations. -- Now will come my unscientific and probably not well enough put together note but hopefully it make some sense: if there is something genetical which makes this disease a bigger problem in the Han Chinese population thne that is very likely to be everywhere unless it's really a very new mutation. On the other hand, it's possible the mutation won't be found in every population in India. Looking at SARS statistics https://www.who.int/csr/sars/country/table2004_04_21/en/ https://www.who.int/csr/sars/country/table2004_04_21/en/ look at the high number of cases in Singapore where 75% is Han Chinese.