The U.S. Constitutionâs 10th Amendment is arguably the most important of all the amendments in the brilliant document that helped shape the United States.
Not even identical twins have the same DNA--although theirs would be far closer than anyone else's. DNA changes over time. Odds of two siblings having the same DNA who did not split from the same zygote are vanishingly small.
September 1, 2015. It seems like brothers and sisters should have the same ancestry background. After all, they both got half their DNA from mom and half from dad. But because of how DNA is passed on, it is possible for two siblings to have some big differences in their ancestry at the DNA level.