Americans From South Asia Are Much More Genetically Diverse Than Chinese Americans

Razib does some basic analysis of with the genomes of Americans ancestrally from South Asia and from China, respectfully. It is summed up in this chart:

In both case, immigration to the United States is not uniform. Some geographic areas and some castes in India are greatly overrepresented. In the case of China:

[T]he American Chinese community has been historically biased toward being mostly Cantonese. More recently, there have been migrants from Fujian.

In the case of South Asia:

[T]he middle Indian cluster are South Indian brahmins who have high levels of ANI and the top cluster is North Indian brahmins/? probably punjabis more in the north. there aren’t many ppl from the cow belt in the USA. some south indian brahmins, but they’ll be in the same position as a lot of gujus.

But, as the chart above illustrates, the genetic diversity of the various South Asian populations that have immigrated to the United States is vast compared to that of the ethnically Han immigrants to the United States from China.

This reflects the underlying reality that South Asia itself has much more genetic diversity than China does.