DNA Question

Can DNA be extracted from the skeleton of a child in a manner sufficient to be compared with the parents’ DNA for ID purposes? In this case, the child has been dead and buried, but not embalmed, approximately 4 months.

Probably from the bone marrow, the pulp of the tooth. I’ve heard of them sequencing with much older remains. But I am not DNA expert.

DNA can be extracted from very old corpses, but the conditions determine whether the DNA will break down. An unembalmed corpse sounds like a possibility. Wouldn’t the authorities be involved in this case? What do they say?

Not a real case. It’s from a TV show. I’m still interested in the factual answer, however.

DNA testing is not an all or nothing thing. It breaks down due to conditions. DNA always makes it easier to prove who you are NOT genetically related to directly rather than proving you are but that also varies with time and DNA sample quality. Four months is a very short time in that context however. It should be fairly easy to prove parental relationships with an incredibly high confidence rate unless the supposed father was an identical twin.

Using current methods, it is possible to go back much, much farther than that. Several hundred or even a few thousand years isn’t out of the question although those are cases where you could more easily rule out parentage rather than prove it. Thomas Jefferson almost certainly had slave offspring based on DNA testing and historical facts but it isn’t impossible that a male relative was the father no matter how unlikely so DNA researchers just state it as a high confidence interval rather than a pure fact.

Here are some old bodies that have been DNA tested with varying degrees of success. For some remains, you can still go back at least 1000 years and get high quality results.

Thanks, Shagnasty. And ruling the child out would work just as well in this instance.

I’m not trying to be cryptic, I just didn’t want to get off on a tangent, but in the current episode of* Bones* a coroner is about to lose her job because she can’t tell whether a child’s remains are of a specific child, even though she has access to the parents’ DNA. It seemed silly to me, but my knowledge of DNA is limited.

I’ve never watched Bones, but if that’s chacteristic of the plots, I’m probably not going to. All the coroner would do is send samples to the lab anyway.

I wouldn’t say it is characteristic, but in this episode it was the device employed to gather up team members from all over the world who had left to pursue other things. Pretty weak.

Traces of DNA have been recovered from T. rex bones. Admittedly, in that case it was so degraded it wasn’t good for much of anything, but that’s a Hell of a lot older than your four-month-dead child.

In the case (recently completed appeal process) of Robert Pickton, who murdered about 50 women in Vancouver, BC - he picked them up over about 10 years, killed them then cut them up and fed them to his pigs. One news story said that most of graduating archaeology students that year had summer jobs sifting through pig manure for evidence. Apparently the pigs were too lazy too grind up the teeth. They found enough evidence with several murders from DNA inside teeth that had been through a pig intestine and buried in manure for years.

I would be surprised if a body only 4 months old did not have useable DNA unless it had been in really interesting conditions. (What? I don’t know)

After 4 months in the ground? Certainly they could get DNA of sufficient quality for genotyping. DNA is a remarkably stable molecule.

Especially from the teeth. Teeth are great at preserving good-quality DNA for a long time. 4 years is nothing.

The TV plot* is stupid if the coroner has the ability to do DNA genotyping.

*“Bones”? never heard of it - is it any good?