In Who We Are and How We Got Here: Ancient DNA and the New Science of the Human Past David Reich makes the observation that India is a nation of many different ethnicities, while China is dominated by a single ethnicity, the Han. This is obviously true, more or less. Even today the vast majority of Indians seem to be marrying with their own communities, jati.
Over the years I’ve collected many different genotypes of Americans of various origins who have purchased personal genomics kits, and given me their raw results. I decided to go through my collection and strip detailed ethnic labels and simply group together all those individuals from India, and China, who have had their genotypes done from one of the major services.
I suspect that these individuals are representative of “Indian Americans” and “Chinese Americans.” So what’s their genetic structure?
Here’s the variation of the consumers:
Merging with 1000 Genomes and some HGDP samples, here’s what I get:
Let’s zoom in on the Chinese:
In case you don’t know, the American Chinese community has been historically biased toward being mostly Cantonese. More recently, there have been migrants from Fujian. The Indian American distribution should be self-evident.