The rate of mutation is faster than that of nuclear DNA.
Explanation:
Molecular clock is a term used to describe the genetic technique that allows the study of evolution at the molecular level, relating the time of divergence between species compared to the molecular differences in DNA sequences or in the composition of proteins.
In this case, the DNA of the mitochondrial and that of the ribosome is more advantageous to be used as a molecular clock. This is because the rate of mutation of these DNAs is much higher than the rate of nuclear DNA. This allows the researcher to identify many polymorphic regions that were generated in an evolutionary process of millions of years. As the mutation rate is constant, the large number of polymorphisms in these DNAs make them the best option as biological clocks
They are not violent killers because they need their host to stay alive for their benefit And if the host dies the parasite wont have a host so they try to keep it alive for as long as possible.
