A negative mutation is one which is harmful to the organism. The result of a negative mutation is a non-sense protein. Examples of negative mutations include:
- a frame shift mutation - codons are read wrong
- an insertion mutation - insertion of a sequence of extra nucleotides
- a deletion mutation - deletion of a chain of nucleotides
- a non-sense mutation - results in the creation of a non-sense protein
- a transition mutation - exchange of purines to pyrimidines thus changing the nucleotide sequence and resulting in a mutation.