"race" is a pseudo-scientific nonsense

"Race" as a biological concept applied to variants of plant species may once have had some value but, applied to humans, is nonsensical except as an indicator of paranoia and intention to apply power; the cross-fertilisation between these two applications has diminished what little value it may have had for biologists.

"Ethnicity" is much more interesting, and does relate to genuine variants in the way people choose to live

The crux of this statement is the use of "choose".

Anthropologists going (usually from urban societies dominated by "whites") to study the inhabitants (mostly not "whites") of societies (mostly nonurban) may have justifiably applied the phrase "genuine variants in the way people choose to live" in an historic sense and there has been considerable scholarly discourse on the very topic, usually contrasted with aspects of "determinism".

But, in our western, Anglo- or Euro-centred societies, constructs of ethnicity are often applied to individuals from outside their groups rather than actively chosen by them. The outwash of the Cronulla riots in Oz include the notion that a "real Australian" (one who mindlessly chants "Ozzie!" thrice followed by "Oy!", also thrice) has no visual attributes that would betray any ancestry from outside a territory bounded by the Atlantic on the west, the Urals on the east (although some of those Georgians are a bit suss), the bits of Scandinavia (without the Lapps) in the North and the Alps and Pyrenees in the south and even the Catalans are a bit dodgy. The "real Australians" attibute foreign ethnicity to anyone else (Indigenous peoples confuse their tiny minds) and tell them to "Go home!" when their targets may have mnore generations of ancestry in Australia than the shouters.

When the targets "choose" a particular ethnicity as a result of such treatment it's usually as a form of negative reaction for protective purposes rather than a positive acclamation of multiculturalism.

Not long ago I listened to a radio interview of a Birmingham (UK) lawyer; the context was the effect of slavery in her ancestry on her ability to identify with any particular culture or ethnicity. Her parents had come from one of the British Caribbean colonies/dependencies but she herself was born in the UK; her public identity was one foisted on her by those around her in the UK. When she went to the particular Caribbean locality where her parents had come from, the locals regarded her as a foreigner on the basis of her accent and assigned her an identity and ethnicity that had very little to do with them. When she visited the part of Africa from which her ancestors had been enslaved, originally,, the locals there also regarded her as a foreigner on the basis of both her coloour and her accent and assigned her an identity and ethnicity that had absolutely nothing to do with them; moreover, she was identified with 'western oppressors'.

So, while I think McGrath's got the right idea, there are "fish hooks" all through almost every line of exploration of the discussion. Which is not an argument for cessation, just one for care. And I know there are 'catters who could have said it much more succinctly.

End of rave!

Cheers, Rowan