a higher and higher % of DMs, emails, etc. to me are from indians asking about their genetics. since there are 700 million indians on the internet. makes sense

i'll be publishing my 6K-word essay in indian genetics https://t.co/ycMGoZh13z

but some general points 1/n

- there's a lot of structure. which means you can look at an indian's genome and get an immediate sense of things and a little digging get's granularity very quickly

eg i guessed @suryasays family's jati after about 15 minutes (he was vague about this and had to ask mom)
- a lot of the variation is not partitioned geographically. very different from europe & china where geography is the dominant predictive variable.

indians have lots of structure which means non-geographical (jati) matter a lot. tamil brahmins more like UPites than other tamils
- the 'india-cline' pioneered by reich patterson is pretty explanatory. on one end you have west eurasian adjacent groups. jatts ppl in the NW and upper caste. and other end something away from them (more toward andamese). dalits, southerners etc.
- some groups are off the cline. that means they are not well modeled by the distribution. e.g.,

* parsies (75% iranian)
* bengalis (5-20% east asian)
- brahmins across india are 'steppe-enriched.' they are more indo-aryan than most other groups (jatts are even more steppe-enriched fwiw). those in the south and east mixed with natives

the rough formula is 75% UP brahmin + 25% "native" (works for bengalis & south brahmins)
- some of the dalit groups seem to have been isolated genetically (no intermarriage) for a long time. also their tend to be more 'inbred' than other isolated groups like brahmins. basically very delimited marriage networks. even though these groups are 15% of india's population
- muslim groups are pretty much like non-muslim groups in their area. lots of ashraf ('foreign') muslims are actually more upper caste hindu in ancestry than west asian (though they may have some of that). the average muslim has no detectable foreign ancestry
- a little bit of outbreeding would probably reduce recessive disease load. it doesn't matter that your 'community' does not do cousin marriage when it's been marrying amongst 3 villages for 500 years
- the distant ancestry of indians is very distinct. one of us some us brown ppl look 'iranian' or even semi-european while others look like africans with straight hair (a term used by a haitian friend). like europeans indians are recent mixes (5-4000 years) but distinct threads
- the indian mix is widespread across most communities and regions with proportions differing. this means that there is no real 'ancient' indian aboriginal group left. the adivasis are social constructions not reflective of anthropological indigeneity
- i suspect indo-aryan and dravidian language is intrusive to most of the subcontinent (s center and east) over the last 5000 years. munda speech certainly is
- i don't want to get bogged down in the 'aryan invasion theory' argument but i would like to see an anthropological case where male-mediated genetic replacement/displacement doesn't have to involve exploitations and subjugation :-)
- indians are very diverse. but if you look at someone from the subcontinent's genomes you can tell they are subcontinental cuz there are some unique aspects

More from Education

** Schools have been getting ready for this: a thread **

In many ways, I don't blame folks who tweet things like this. The media coverage of the schools situation in Covid-19 rarely talks about the quiet, day-in-day-out work that schools have been doing these past 9 months. 1/


Instead, the coverage focused on the dramatic, last minute policy announcements by the government, or of dramatic stories of school closures, often accompanied by photos of socially distanced classrooms that those of us in schools this past term know are from a fantasy land. 2/


If that's all you see & hear, it's no wonder that you may not know what has actually been happening in schools to meet the challenges. So, if you'd like a glimpse behind the curtain, then read on. For this is something of what teachers & schools leaders have been up to. 3/

It started last March with trying to meet the challenges of lockdown, being thrown into the deep end, with only a few days' notice, to try to learn to teach remotely during the first lockdown. 4/

https://t.co/S39EWuap3b


I wrote a policy document for our staff the weekend before our training as we anticipated what was to come, a document I shared freely & widely as the education community across the land started to reach out to one another for ideas and support. 5/
https://t.co/m1QsxlPaV4
Working on a newsletter edition about deliberate practice.

Deliberate practice is crucial if you want to reach expert level in any skill, but what is it, and how can it help you learn more precisely?

A thread based on @augustbradley's conversation with the late Anders Ericsson.

You can find my complete notes from the conversation in my public Roam graph:
https://t.co/Z5bXHsg3oc

The entire conversation is on

The 10,000-hour 'rule' was based on Ericsson's research, but simple practice is not enough for mastery.

We need teachers and coaches to give us feedback on how we're doing to adjust our actions effectively. Technology can help us by providing short feedback loops.

There's purposeful and deliberate practice.

In purposeful practice, you gain breakthroughs by trying out different techniques you find on your own.

In deliberate practice, an expert tells you what to improve on and how to do it, and then you do that (while getting feedback).

It's possible to come to powerful techniques through purposeful practice, but it's always a gamble.

Deliberate practice is possible with a map of the domain and a recommended way to move through it. This makes success more likely.

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