Race ia a grouping OF a (large) number of people based on UNCONTROLLABLE significant common physical characteristics (defined by your DNA. Ethnicity is a grouping of people on the SELECTABLE basis of common real world characteristics C, where C can be derived from the physical, cultural, locale etc. "I use them interchangeably - am I wrong?" Yes.
The simplest way to put it is probably that race is what you're born with and ethnicity is picked up. Both are fairly hard to define and quite complicated, though. Harry Kane and Dejan Kulusevski are arguably the same race but different ethnicities, for example.
The "ashkenazi" is a known race genetic subset. If I did a DNA read of every Caucasian alive, and every "Jew" , and started doing genome subsequence matching, you will soon see if there is a significant % of the genome particular to "Jews" but not Caucasians as a whole. "It doesn't matter whether they were right or wrong if it was the cornerstone of their belief. Bringing in discussion about "different groups of white people" is also not very helpful." Nazi ideology = fascism + "master race" , where "master race" = subset of Caucasian labelled "Germanic" (or "Aryan" ) .
If I state my ethnicity as "Christian" , or "Muslim" , what physical properties define any of the above ??
That wasn't the part that I was calling debatable. Race being a physical construct was. What race is Barack Obama, for example? If mixed, then at what point is somebody not mixed? 20%? 10%? 3%? If someone's part North African and part West African are they mixed race? It's all a bit imprecise and messy.
Having looked into it I'm not sure this is right. Ethnicity seems to include cultural choices but familial background is also part of the equation.i couldn't be an ethnic Jew as (as far as I know) none of my family were/are Jewish. I'm very much a one race = human race kind of guy by the way.
Racial "purity" conforms to the Pareto distribution. If my genome is in the "long tail" of the curve for X, then I probably shouldn't be calling myself X. The mathematical way is to define new super/subsets that encapsulate the prevailing racial proportions. But super/sub sets can result in "combinatorial explosion" , which can be quite .... "messy" . So mathematics is telling you that trying to operate a system on the basis of race sets, is probably not a good idea.
It could be argued that familial background has some basis in the physical (a deep genetic embedding to protect/favour an "in group" etc) . However it not a painfully unseverable for humans (well, it isn't/wasn't for me) .
Interesting take on the Southend By-election result from the Tory Candidate and new MP... Claiming level of victory as support for Johnson in an election in which she was unopposed by leading Parties but still managed to reduce her majority!