Asked by: Sofia, Manchester
Yes. You inherit exactly half of your father's genes, so checking 16 genetic markers on both of you is enough to be 99.99 per cent confident that someone is your father. Brothers also share half their genes with their other siblings, but only on average - the exact relatedness varies. By comparing lots more genetic markers, a DNA test can show that two siblings are very closely related but can't be father and son (or father and daughter) because the genetic relatedness isn't exactly 50 per cent.
Read more:
- Is it true that a son will always grow to be taller than his mother?
- Are we closer genetically to our parents or our siblings?
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