There is no question that there are differences between population groups. To give two of many examples, the same Ashkenazi Jews mentioned in the Guardian article are subject to a couple of devastating diseases not often found in the human species at large. Individuals descended from certain population groups in Africa are much more likely to come down with a condition commonly known as sickle-cell anemia.

However, these predispositions have nothing much to do with the more common use of the word "race", which is based primarily upon skin color and certain facial features and includes certain assumptions. For example, an individual in the US with a very minute percentage of African descent is usually considered to be "Black" (normally some shade of tan-brown) or "African-American", regardless of his or her physical appearance or cultural orientation. There is only one race - the Human one.