buried the lede, imho: we have enough DNA profiles to match their sampling up with.
I'm always stunned when reminded that a full genome sequencing has gone from Human Genome Project's extreme cost and (edit: glacial) speed to using seqencing as the easy button.
I hear we've also got machines that'll seqence, fit on a bench, and cost high five/low six figures. They've got issues to work out still though- iirc something about damaged sections causing issues.
Paleontology has been really helped by the ease of sequencing, to the point where many evolutionary arguments are moot. Humans are apes, birds are dinosaurs. Some people still dispute it, but not with evidence on their side.
Should be noted, though, the cheaper/quicker techniques do still come with compromises compared to the "gold standard" technique used for the Human Genome Project.
I was chatting with a biologist friend a while back, and one tidbit he dropped in was that any sample of air from anywhere on earth will likely contain the dna of organisms unknown to science, so abundant the tree of life is.
I do often wonder about stories like this in the context of forensic science – my (incomplete!) understanding a lot of the time suspect DNA samples are taken from small areas and amplified significantly with high-cycle count PCR. I'd worry that any jury presented with a statistical argument about a fragment of somebody's DNA being very unlikely ("1 in 100 million") to be different to the sample found at the scene would not be aware of all of the potential systematic reasons why the actual true probability may be much, much higher.
Forensics never relies on a single piece of evidence. It takes several corroborating accounts and pieces of evidence to reach "beyond reasonable doubt."
This is why even breathalyzers have to be done twice, with a gap in between (and preferably with different sensors). It's also why several witnesses are examined. It's why fingerprints and lie detectors alone don't pass the muster. Nearly anything can be faked, or misinterpreted. All these things have to be used together to create an unbreakable story.
So there is next to no risk with DNA in the air.
As an example, there recently was a guy who went into a police station and claimed that he was relocating there from another province. The officer on duty was suspicious, and found there was no record of this officer in the entire country, and arrested him. In court, the guy got off the hook, even after impersonating a police officer and trying to infiltrate a station, because the officer on duty did not collect the appropriate evidence. The camera footage looked entirely normal. It became entirely hearsay.
You can pretty much expect him to charge that officer with wrongful arrest now.
We may never know what that guy was up to. But he certainly had chutzpah!
This always blows my mind. We are currently breathing in the DNA of the trees, animals, and people around us—and we’re leaving ours behind for them, too. We’re all one big genetic soup.
People thinking how complicated this must be to filter through for forensics, forget that during and following the Covid lockdown, cities monitored sewage water for Covid viral load. They even recognized and reported the specific strains and their dominance in the samples. This includes finding "new" strains, and all this among all the other DNA/RNA bits to be found in city sewage.
So the technology is indeed there to find the needle they're after in the haystack they're provided.
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[ 2.7 ms ] story [ 23.6 ms ] threadI'm always stunned when reminded that a full genome sequencing has gone from Human Genome Project's extreme cost and (edit: glacial) speed to using seqencing as the easy button.
I hear we've also got machines that'll seqence, fit on a bench, and cost high five/low six figures. They've got issues to work out still though- iirc something about damaged sections causing issues.
This is why even breathalyzers have to be done twice, with a gap in between (and preferably with different sensors). It's also why several witnesses are examined. It's why fingerprints and lie detectors alone don't pass the muster. Nearly anything can be faked, or misinterpreted. All these things have to be used together to create an unbreakable story.
So there is next to no risk with DNA in the air.
As an example, there recently was a guy who went into a police station and claimed that he was relocating there from another province. The officer on duty was suspicious, and found there was no record of this officer in the entire country, and arrested him. In court, the guy got off the hook, even after impersonating a police officer and trying to infiltrate a station, because the officer on duty did not collect the appropriate evidence. The camera footage looked entirely normal. It became entirely hearsay.
You can pretty much expect him to charge that officer with wrongful arrest now.
We may never know what that guy was up to. But he certainly had chutzpah!
Testing relies on amplifying many parts of the human DNA not just a small fragment.
The smaller the fragment the less precise the comparison.
So no, floating DNA does not meaningfully impact testing. It can impact PCR assays that target small regions for identification eg of viruses.
So the technology is indeed there to find the needle they're after in the haystack they're provided.