My understanding from a genealogy perspective (I’m a non-Jew so correct me if I’m wrong) is that most Jews have a blood link to the Israelites somewhere. Ashkenazi Jews are basically a mix of European and Semitic peoples, for example. Ethiopian Jews are mostly African but even they are thought to have a little connection to the “original” Jews via the Tribe of Dan.
However, anyone who converts is accepted as a Jew, and their genes then of course mix in with the rest of the Jews they live and worship among as they marry, have children, etc...
Is that at least somewhat correct?
They did a study and pretty much all Jewish people are related to the 3rd or 4th cousin level, regardless of Sephardi, Ashkenazi, or Mizarahim, if that is what you mean.
Our closest non-Jewish genetic relatives are the Samaritans (who never left), followed by the arabs who live in Judea/Samaria (also known as “palestinians”).