How does one identify a jew by site? How do you differentiate between a Roman nose and a jewish nose? How do you identify a jew by ancestry? Ancestry.com seems like shit, how do you go about lining up some random dude's family tree and searching it for traces of sneaky hebrews?

I've met a super cool dude who is both /fit/ and /k/ and 90% /pol/, but he has the most hawkish look and the biggest hooked nose. His name is a German name, and his dad doesn't resemble a camel like most Ashkenazi as they age. Maybe it's just a Roman nose but I'm only about 50/50 at identifying jews and I want to be absolutely sure. Guides and resources please?