Question

Sickle-cell anemia is caused by a single point mutation in the hemoglobin of human red blood cells. It is a recessive gene. People who have sickle cell anemia are homozygous recessive and suffer terribly from this disorder. Now I have stated in lecture that mutations are neither good nor bad. Rather it depends on how the mutation effects the survival of the species. If the mutation harms the survival of the species it is bad, if it helps the survival of the species it is good. Now tell me is this mutation good or bad? What do you think?

Answer 1

Of course here in the case of sickle cell anemia, the mutation is bad. But mutation does not cause harmful effect all the time. In some cases mutation helps the survival of the species. The best example include the mutation in bacteria which make them resistance to antibiotic. It means here mutation enhances the survival of bacteria in the presence of antibiotics. Another best example include almond seeds which contain amygdalin in wild species which convert into cyanide in human body which may be lethal. A single gene mutation in almond tree resulted in a tree free of amygdalin. When humans discovered this non-amygdalin almond species, they cultivated them, which is continued till today. Thus, mutation is not always harmful.