What causes the differences in genetics
Despite the fact that they do have a lot of DNA in common, identical twins are not exact replicas of one another because of glaring genetic abnormalities.
What accounts for the greater genetic diversity in certain twin pairs than in others?
There is a correlation between the frequency of twinning and the likelihood of genetic mutation. An increased likelihood of mutations results from earlier twinning splits, which give each zygote more time to generate DNA separately as it develops.