I've read up on what defines a Jew and as far as I've ever found there's no DNA marker like there is with other ethnic groups. My wife is Cherokee, for example, and if need be a blood test proves she's a Native American. I gather they can now narrow it down to which tribe these days if anyone cares.
I've never read of anything similar regarding the Jews but maybe you could point it out for me.
You're free to define yourself and your fellow Jews however you like but it comes down to hot air IMHo without the same sort of DNA proof other ethnic groups rely on.
I am not Jewish.
I go by the definition of Jewish Law, Israel and most scholars.
Israel is very involved in Jewish genetic research. They are a genetically identifiable ethnic group.
I will point you to reading material later today.