Genetics Question (Spoilers for Continuum Season 2)

[Rabulias]

So in Continuum, a bunch of people get sent back in time to various points in the past from the year 2077. Most of them end up in 2012.

A teenager today, who becomes a brilliant, rich, and powerful man in the future, believes that a man sent back to 1990 is his father. So he surreptitiously grabs some DNA samples from the guy and has them tested. The results come back with a 99.9% likelihood that he is the young man's father. Later on it is revealed that the man is actually the teenager's future son.

My question is this: are the paternity test results plausible in this case?

I love the time travel twist on this scenario, and I think it's clever and entertaining, but could it happen?

 

[PigKnight]

DNA tests only say that they share DNA strands. So sure. Why not?

 

[Kramodlog]

Well, your dad and your son will both have 50% of the same genetic material than you. So I guess it can be accurate, but I am no geneticist. I do not have those kinds of prejudices.

 

[Umbran]

By my understanding, yes, that works. Half of your DNA comes from your father. Half your son's DNA comes from you.

Given just the two samples, you cannot tell which is the son, and which the father - only that they are related.

 

[Ragnar_Lodbrok]

Makes sense according to my understanding of it, as well.

 

[Mustrum_Ridcully]

I am thinking about whether there might be a way to see the difference via the mitochondrial DNA, which is only inherited by the mother. But I can't think of a scenario here where it would tell you anything useful.

Logically, they two should have different mitochondrial DNA, since they won't have the same mother* or mothers that are related. But that could only be used to show they can't be brothers.

*) though time travel... who knows?