An interesting article in the latest issue of New Scientist hypothesizes that the duration under which particular areas of Europe were under the rule of the Roman Empire has a correlation with the lack of the CCR5-Delta32 receptor.

In countries inside the borders of the empire for longer periods, such as Spain, Italy and Greece, the frequency of the CCR5-delta32 gene, which offers some protection against HIV, is between 0% and 6%.

Countries at the fringe of the empire, such as Germany, and modern England, the rate is between 8% and 11.8%, while in countries never conquered by Rome, the rate is greater than this.

It is also suggested that the Roman occupations caused a reduction in the population of those that possessed the the CCR5-Delta32 variant, as these people were were particularly susceptible to a disease introduced by the occupiers. As the Romans moved north, this disease killed off people with the variant.

Click here to read the article