People can only get the sickle cell gene at the time of conception. Neither the sickle cell disease or trait can be contracted later in life. If you have the sickle-cell trait, it also doesn't go away as you get older. A person born with the trait or disease will always have it but the severity of the disease can change through time. The change in the severity is also not due to a change in the sickle cell genes over time but instead a number of other biological factors. People who inherit two genes have sickle cell disease. With exceptions, a child can also inherit sickle cell disease if both parents have one gene for sickle cell hemoglobin. This is common when each parent has one sickle cell …show more content…
They conducted the experiment by collecting blood samples from 3,959 people and 21.7% has the sickle cell trait genotype and 52% showed evidence of Plasmodium infection. Their experiment showed that an increase in malaria of 10% is associated with an increase of 4.3% in Sickle cell trait presence. They also showed that age is also associated with sickle cell trait prevalence. They came up with two hypotheses to explain how age is associated. Their first hypothesis was that the selective pressure of malaria has decreased within time due to improved health care. Their second hypothesis was that the genotype that gives rise to the sickle cell trait shows protection against severe malaria in adult life and childhood. According to this same article, another research was done by Sarah Tishkoff and Scott Williams. They looked at the relationship specifically in Africa and realized that there is a growing body of evidence showing "recent" human evolution can be due to environmental impact but the Elguero study argues that it is still happening in the relationship of malaria and sickle cell trait. (Sriskantharajah,