Question

Describe the experimental basis for the following fundamental principle about mutations:

“The mutational process is random in the sense that whether a particular mutation happens is unrelated to any adaptive advantage it may confer on the organism in its environment. A potentially favorable mutation does not arise because the organism has a need for it.”

Answer 1

Mutations are always random. They are due to errors in DNA copying or due to erors in meiosis. Most of the errors get corrected soon after the replication. But some errors remain to cause mutations in the organism. There are certain mutations in the organisms which are not of any use to the organism. They infact even can be of inconvenience to the organism. For example the very big antlers which we see in some cattle cause lot of difficulty to the organism because of its weight. The long tail in peacock prevent it from flying because of its weight again. If all mutations are useful and beneficial to the organisms , these mutations must not have originated in these organisms. Sickle cell anemia is a disease which causes the RBCs to become crescent shaped and a person suffers from anemia in the entire life.

All these mutations may not have occured if mutations occur due to the need by the organism.

Cells subjected to UV rays can cause number of DNA changes which can give rise to cancers. This is one proof that the mutations are not always need based in the orgnisms.