SAVED BY THE BLACK DEATH ?

Human beings have evolved in response to parasites in the past and it’s possible that some of those adaptations may be protecting some people from HIV today. After collecting blood samples from people who are at high risk for being exposed to HIV, their DNA was analysed. On comparing the genes of people who were infected with HIV to those who haven’t, several different teams of scientists discovered that in order to enter a white blood cell, HIV has to pry open a receptor on the cell’s surface called CCR5.
The scientists came across a mutation to CCR5. The mutation ruined the protein that the CCR5 is supposed to create. As a result. People who carry two mutant copies of CCR5 have no CCR5 receptors on the surface of their cells and be repeaatedly exposed to HIV and yet resist it completely. People who carry only one mutant copy of the CCR5 make fewer CCR5 receptors than normal and this mutation slows down the onset of the full-blown AIDS for two to three years.
This mutation was most common in Europe and was missing from the rest of the world altogether. Whatever favoured the gene among the Europeans took place about 700 years ago (this was determined by the age of the DNA that surrounds the CCR5 mutation) And it turns out 700 years ago something was putting Europe under Massive NATURAL SELECTION: The BLACK DEATH