Jewish and Middle Eastern non-Jewish populations share a common pool of Y-chromosome biallelic haplotypes.
M. F. Hammer, A. J. Redd, E. T. Wood,  M. R. Bonner, H. Jarjanazi, T. Karafet, S. Santachiara-Benerecetti, A. Oppenheim, M. A. Jobling, T. Jenkins, H. Ostrer, and B. Bonné-Tamir. Proceedings of the National Academy of Sciences, May 9, 2000.

Abraham was the first Jew, but Adam was the first Judaist. A "Jew" is not simply someone who follows Judaism, but a member of a people who are regarded as a priestly nation amongst those who follow Judaism.  The Noahides also follow Judaism but are not part of the Jewish people.

The high ages attributed to the people in early Jewish history are a mystery. Although it is considered highly unlikely that people lived to such advanced ages and moreover bore children, there is no proof that it is impossible. Their genetic disposition could have been such that they aged much slower than modern man. Attempts to explain the ages as referring to shorter periods do not work - attempting to scale the ages to that of modern man results in children being born to prepubscent parents. Another commonly cited explanation is that the ages reflect a belief in reincarnation and that whole generations of people were considered to be one person. If this is the case, people described as being sons may in fact be descendents.

The word "Semite" is a form of the word "Shemite".  According to a defunct 19th century hypothesis, speakers of the so-called "Semitic languages" all belonged to a so-called  "Semitic race".  This idea is not accepted by modern anthropologists. It is in fact not known what language the Bnei Shem spoke let alone if it was "Semitic" and moreover, not all speakers of the so-called Semitic languages were descended from the Bnei Shem. Consequently the word "Semite" is no longer used, the term "Shemite" being the preferred English for Bnei Shem, and "Afro-Asiatic" being the preferred name for the language family containing Hebrew, Aramaic, Arabic, Coptic etc.)