Ethnicity Assignment: A Cultural Process

A brief muse on a longstanding theme of mine - that ethnicity assignment is a very different process than genetics, with the only commonality being that one of the salient features for ethnicity assignment - skin colour - has strong (and very complex) genetics.

— Ewan Birney (@ewanbirney) March 27, 2023

It's worth reminding people that there is not a set of universal ethnicity categories; the categories provided in forms are inherently cultural. The US census has one set; UK recording another; Germany one more; India v. different + in France it is illegal to ask about ethnicity

— Ewan Birney (@ewanbirney) March 27, 2023

Many of these categories came about during the end of the 19th Centuary when science was getting into classifications of all things, and much of this wrapped up in the justification of (continuing) slavery or of segregation.

— Ewan Birney (@ewanbirney) March 27, 2023

Slavery is clearly immoral, but was widespread (and continues to today) and the industrialisation of slavery in the transatlantic slave trade, coupled with chattel slavery (the children of slaves are slaves, with the "one drop" rule) was horrific.

— Ewan Birney (@ewanbirney) March 27, 2023

Segregation - whether the formal Jim Crow laws in southern US, Apartheid in South Africa or the less formal race riots in port towns in the UK in 1920s - and much more - all hinge on ethnicity/race classifications being *meaningful* and inherent.

— Ewan Birney (@ewanbirney) March 27, 2023

ie, it is possible to sort people into groups, and these groups have inherent differences.

— Ewan Birney (@ewanbirney) March 27, 2023

Perhaps unsurprisingly the birth of human genetics was closely intertwined with the support of these classifcations and the (now discredited) science of improving human population via selection breeding, ie, eugenics.

— Ewan Birney (@ewanbirney) March 27, 2023

We now know very clearly that genetics although not 100% random wrt to any particular ethnicity classifications (because... human populations are complex) just don't align to any concept of "groups of humans" and even less the ethnicity terms thrown around.

— Ewan Birney (@ewanbirney) March 27, 2023

An important thing to appreciate is that humans have adapted to the very varied environments worldwide predominantly via behaviour - we've made weapons, clothed ourselves from the cold, dug up tubers and cooked, made canoes, kayaks and ships, and houses and cities.

— Ewan Birney (@ewanbirney) March 27, 2023

We pass these behavioural adaptions down by behaviour - teaching - a high complex scheme that allows for long lasting cultural transmission between humans. It's our "secret sauce" and its powerful stuff.

— Ewan Birney (@ewanbirney) March 27, 2023

As such our genome has had surprisingly little to adapt to as we moved around the world. One thing is (probably) vitamin D levels, which needs UV light, hence skin colour. There are some other oddities, like alcohol tolerance and lower sweat gland density

— Ewan Birney (@ewanbirney) March 27, 2023

...but these genetics adaptions is the minor side, and these adaptions themselves mix quickly and in complex ways because humans like to migrate and have sex

— Ewan Birney (@ewanbirney) March 27, 2023

The end result is that our genetics is complex and recent (our genetics defintiely does not look like other species with lots of individuals with a global distribution) and ... certainly just doesn't map to ethnicity.

— Ewan Birney (@ewanbirney) March 27, 2023

In some sense this obvious. A box you tick out of ~30 boxes is not going to represent genetics, a sort of 300,000 dimension complex thing, best represented as a complex, interwined tree.

— Ewan Birney (@ewanbirney) March 27, 2023

The presence of the "Mixed race" box and catch all "Other" shows just how continuous mixing is (humans... move around and have sex). As is "Latino" from the complex, often brutal, mixing of Europeans (mainly Spanish) and native southern americans.

— Ewan Birney (@ewanbirney) March 27, 2023

Indeed, "Europeans" are themselves a complex mixture with at least 3 rather distinct contributors; stone age hunter gatherers, the technology whizzes of 10,000 BC , Anatolian Farmers and the pasturalists from around Ukraine (Yamnaya people)

— Ewan Birney (@ewanbirney) March 27, 2023

And these groups were pure - nothing is pure - its endless, complex, mixing, all the way back to our species' birth place in Africa (somewhere, itself probably more complex).

— Ewan Birney (@ewanbirney) March 27, 2023

I find understanding this powerful; ethnicity is a construct society has made, often for harsh, brutal and badly motivated reasons. Once you understand this, we can leave it behind or at least place it into context

— Ewan Birney (@ewanbirney) March 27, 2023

In modern society, ethnicity is wrapped up with identity, a new way of talking about an old thing - in-group vs out-group, modern tribes. Its depressing to watch these castles built in people's minds and the repeated harm that comes from this thinking

— Ewan Birney (@ewanbirney) March 27, 2023

The human behaviour of in-group/out-group is powerful (to stress - I am no behavioural expert; I am a genetics expert) and I don't think we can banish it simply be stating its harms.

— Ewan Birney (@ewanbirney) March 27, 2023

We need education; we need to know our collective history and how these human themes repeats; we need places where the tribal feelings can be put safely - sport being a prime example.

— Ewan Birney (@ewanbirney) March 27, 2023

One part of this education is up to date human genetics; understanding that genetics is far far messier and more complex and not directly related to ethnicity (despite this intersection around skin colour).

— Ewan Birney (@ewanbirney) March 27, 2023