These genealogies cover many of the ancient peoples who lived in the Mediterranean Basin, including the Greek islands, North Africa, Turkey, the Near East, Persia, and the Caucasus. Nevertheless, while some of the eponymous ancestors of the peoples mentioned in these lists are easily identifiable (e.g. Mizraim, which is identified with Egypt), others are subject of dispute among scholars. In some instances, names repeat themselves in different listings. Dodanim (10:4) is listed as a son of Javan (possibly identified with the Ionians) the son of Japheth and could be a reference to the inhabitants of the Dodecanese Islands, yet "Dodanim" is also the plural form of Dedan (10:7), who appears as the son of Cush, who was the son of Ham. A similar problem occurs with Ashur, the legendary eponymous ancestor of the Assyrians, who appears in the Ham narrative (10:11) and as a descendant of Shem (10:22). Also Aram the son of Shem not to be confused with the Aramean descendants of Arphaxad. Further compounding the problem is the combination of peoples, places (e.g. Tarshish, or Tarsus), and personal names (e.g. Nimrod) in the groupings.
The biblical grouping into three "families" of nations, while convenient, is not based on any of the modern methods of classifying ethnicities by common origins, language, or other cultural components. Rather, it seems to reflect the attitudes of the ancient Hebrew authors of the Bible toward their neighbors. Those with whom the authors felt the closest affinity were grouped as descendants of Shem, those with whom there was the deepest animosity were grouped as Ham (who's son Canaan was cursed by Noah), and the foreigners who were invading their shores from across the sea (Yavan) or from the East (Medes) were identified with Japheth. This latter identification is corroborated by Genesis 9:27, "God shall enlarge Japheth (literally: 'beautify Japheth'), and he shall dwell in the house of Shem." In Hebrew, this verse uses a pun on the name Japheth, which comes from the Semitic root Y-Ph-T and means beauty: the verse is apparently a reference to the cultural innovations that these newcomers brought to the region.
Nevertheless, this classification survived until relatively recent times and is even the basis for some of the modern nomenclature used to describe the languages of the region. Most Afroasiatic languages for instance are called Hamitic. Those languages related to Hebrew are called Semitic. Though ironically Arphaxad's descendants (who include the Arameans) are the only Shemite people who spoke so-called Semitic languages while some of the other groups (such as the "Hamitic" Canaanites) did.
Their Use as Justifications for Racism
Under the aegis of the Bible, this idea was also used as a justification for racial and ethnic divisiveness that persists until today. Japheth, who was identified with Europe, came to represent beauty (see above) and eventually, cultural superiority. Canaan (the son of Ham), on the other hand, was cursed by Noah: "Cursed be Canaan; a servant of servants shall he be unto his brothers" (9:25). With Ham identified as Africa, this line was later twisted to justify slavery though the line clearly indicated the Canaanites would be slaves even of the other Hamites -Kush, Phut & Mizraim.
Today, however, scholars are practically unanimous that the genealogy reflects the ethnic groupings and changing socio-political alliances of the time and place of the text's composition rather than any genuine history of human origins.