DNA/Paternity Test Determination?

Q: A man and a woman go and take a DNA test to determine who the father is for a child. The DNA test reveals that the man is the biological father of the child. However, it also shows that the mother and the father also share a lot of the same DNA as well. Is this unusual? I know that some two people will carry some of the same DNA, but if this is so, could the DNA test be accurate?

A: No, not usual at all. Two people don’t carry “some of the same DNA.” They have a little more than 99% of the same DNA. Less than two percent differentiates us from each other. (Less than five percent differentiates us from chimpanzees.)