30. HIV-resistant gene mutation
The HIV/AIDS epidemic is horrible despite the amazing medications currently present for it. The disease originated in chimpanzees somewhere in Western Africa and ended up transferring to humans as we hunted these creatures down for meat and ate them. This is why HIV is transferable both sexually and via blood. Yet some happen to be resistant to it.

Studies went into this and found that a gene mutation known as “CCR5-delta 32” can be found in some human beings today and it makes them naturally resilient to the HIV Virus. Without HIV, AIDS also cannot happen in these people either. Scientists were able to trace this back over 700 years to the time of the Black Plague. They were able to uncover that those with this gene could have likely survived the plague and passed on this gene to their offspring.