Understanding Sickle Cell Anemia
How did Tony Allison’s early life experiences in Kenya prepare him to make the discovery of the sickle cell-malaria link?
The early life and experience of Tony Allison while in Kenya prepared him well in his future discovery of sickle-cell malaria. When he was young, Tony suffered from malaria when he went on a trip to Kenya. The experience of Tony with sickle-cell diseases changed his medical motivation and decided to gather more knowledge in the field of naturalist or anthropologists. Tony chose to enroll in school at Witwatersrand in Johannesburg, where he met his mentor in the study of human Robert Broom. Tony thus focused on gaining experience in archeology and physical anthropology by looking for bones to study the origin of humans. During his last years at Oxford University, when training medicine, Tony discovered genetics like blood group gave a better understanding of the human relationship. During his research on different blood types, Tony discovered that the tribes living on the Kenyan coast or around Lake Victoria had a high frequency of sickle-cell carriers than those who lived in Central Kenya or the highlands. The discovery made Tony realize that coastal region was in the low-lying regions where malaria infection was high compared to highlands, where cases of malaria are few. The discovery made tony connect his experience when he contracted malaria at a young age. The connection made him understand the relationship between sickle-cell and malaria.
A balanced polymorphism is when two alleles are maintained at a gene locus in a stable way over time, even if one allele has a detrimental effect on survival or reproduction. What makes the sickle-cell mutation a balanced polymorphism?
Sickle cell anemia is a balanced polymorphism since the heterozygotes provide an advantage over both homozygotes. A person who has heterozygote at a certain gene locus reveals a higher fitness compared to a homozygous individual since the person reveals a balanced polymorphism. The factor is contributed by the balance that exists between the two factors in the proportion of the person with sickle cells. Diseases like malaria can remain prevalent when heterozygotes have an advantage over the individual who has two copies of wild alleles. These two factors explain the severity of malaria, which leads to high chances of occurrence of the sickle cell genes. Also, the factors increase the elimination rate of the gene on people who are dying of sickle-cell anemia. Balanced polymorphism is revealed by the presence of a career that has advantages that allow persistence of a detrimental allele in the population. This form of polymorphism contains heterozygosity of ana inherited illness that protects against infectious diseases. In his research, Tony found that sickle cell carriers have an advantage when living in a malaria-ridden environment since the sickle cell parallels the cultivation of crops, which offers breeding grounds for female anopheles mosquito. According to Tony, individuals who inherited one copy of sickle cell allele had a red blood cell membrane which did not admit the parasite. Carriers passed the protective allele to the population leading to the rise of sickle cell allele from 0.1% to 45% in the Easy Africa region.
Why was the demonstration of human resistance to malaria relevant to evolutionary biology?
The demonstration of human resistance to malaria that was discovered by Tony is essential to evolutionary biology since it proves that the agent of the natural section is still active. The discovery of Tony is crucial since the degree of resistance to sickle-cell is measurable and essential in early life. Tony challenged an existing belief that gene mutation is dangerous by showing some benefits derived from a mutation in disease resistance. BBS mutation has proved to be very beneficial in some cases, like in the treatment of sickle-cell malaria, although t is harmful in some other conditions.
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