There’s a point here. Making ethnicity purely a matter of genetics is excessively simplifying a complicated interplay of culture, faith, and heritage. There’s also no perfect test to determine what someone’s true ethnicity is.

If a single boy is adopted by a family and is raised in their faith, principles, and culture, is his offspring truly a continuance of this “family”? From a genetic standpoint no. from a spiritual standpoint, to a large extent, yes.

If a family adopts twelve children, all of whom were allowed to do “what feels right” while the parent’s two children were inoculated in the parent’s values, are the adopted kids really a continuance of their family in any way? Of course, “no.”

In this case, the Algerian is probably more Greek than Algerian, all things considered. But he is a very strong exception to what a Greek is, not the rule.