Science does not separate people into three main races. Even the early scientist J F Blumenbach, writing in 1793, suggested there were at least five races, not three. The idea of three races exists only in popular imagination and has never been a scientific concept. If we divide the world into Caucasian, Mongoloid and Negriod (the most common tripartite division) where would we put people like the Australian Aboriginals or the Melanesians? They clearly don't fit into any of those three categories. Racial studies as a branch of anthropology declined after 1945, despite a few late hold-outs like Careton Coon. Once we started looking at human variation via biochemical markers such as blood type and (since the 1970s) DNA analysis, it became obvious that there is much more human variation than could possibly be accounted for in 5, 7 or even 30 races. There is a continuous spectrum of variation across the whole planet, with no clear boundaries between any populations. The portion of the book of Genesis in the Bible which describes Noah and his family is attributed to the anonymous writer called the "Yawist". These passages date from the period after the Babylonian Exile, probably around 500 BC - hence they are among the most recent parts of the Old testament, despite being located in the first book. 'Shem, Ham and Japeth' is at etiological story to explain the existence of the three main continents and populations known to the ancient Israelites of the time: The Middle East, Africa, and Europe. Obviously the Israelites had a very limited knowledge of the wider world, so their legends did not attempt to account for the many other groups of people that exist in the world. Hope it helps.