Second, the Tannaim may have been influenced by Roman law, which dictated that when a parent could not contract a legal marriage, offspring would follow the mother.
Opinion polls have suggested that the majority of Jews see being Jewish as predominantly a matter of ancestry and culture, rather than religion.In Orthodox Judaism the child of a non-Jewish mother can be considered Jewish only by a process of conversion to Judaism.The Orthodox and Conservative branches of Judaism maintain that the halakhic rules (i.e. Reform and Liberal Judaism do not accept the halakhic rules as binding, and most branches accept a child of one Jewish parent, whether father or mother, as Jewish if the parents raise the child as a Jew and foster a Jewish identity in the child, noting that "in the Bible the line always followed the father, including the cases of Joseph and Moses, who married into non-Israelite priestly families." (However, according to the oral tradition of Orthodox Judaism, the spouses of both Joseph and Moses converted to Judaism prior to marrying them.) The Reform movement's standard states that "for those beyond childhood claiming Jewish identity, other public acts or declarations may be added or substituted after consultation with their rabbi".This presumption of the status of the offspring of any mixed marriage is to be established through appropriate and timely public and formal acts of identification with the Jewish faith and people...Depending on circumstances, mitzvot leading toward a positive and exclusive Jewish identity will include entry into the covenant, acquisition of a Hebrew name, Torah study, Bar/Bat Mitzvah, and Kabbalat Torah (Confirmation).