Mutation, being a change in the nucleotide sequence of a gene could be lethal. Although, some are not lethal even when they cause serious changes in the gene expression of the individual. That is because such change is to be recorded and examined. But that area will be in my next academic meal post.
Most mutations are unanticipated and their cause is unaided. Such mutations are referred to as spontaneous mutations. Therefore, spontaneous mutation occurs when mutations arise in the absence of known mutagen treatment. This is the ultimate source of natural genetic variation that is seen in populations.
Spontaneous mutations are hard to study since the source, cause, and time of occurrence are not known. Therefore, they attract research interest.
An example is seen in coming across a human with a very big and enlarged ear. Since the cause is not known, researchers will be concerned about the possible cause.
Let us meet in the next academic feed.