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.
Depends on how they're using it. To find an unknown person and prove they were at a scene - yeah you'll have the 100 person's worth of DNA to sort through and then match against a (presently) incomplete DNA database. But if you already have a suspect and need to place them at the scene, if their DNA is one of the 100 then they have shown that.
That's something that would have to be addressed at the trial by the defense attorney raising challenges.
If the DNA is present, it's present - barring any procedural mistakes by the forensics technicians (mislabeled sample, dirty lab equipment, didn't follow manufacturers instructions, etc). Or deceit by one or more members of the forensics team to implicate the suspect.
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.
there’s youtubers that have videos about doing this in a home wetlab. very achievable. some amateur soil biologists using this to try and sample microdiversity as the planet… humanifies.
Ex-Nanopore employee here. One interesting thing we heard about internally was that OceanX[0] has one of our GridION[1] devices (slightly larger, and built-in compute) that they were using to track whales in the ocean by sequencing DNA found in seawater. Really cool.
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.
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.
The immune system destroy all the DNA in unexpected places in case it's a https://en.wikipedia.org/wiki/Viroid or something. Better safe than sorry.
One of the important steps in mRNA vaccines was to surround the mRNA with a lipid to ensure it can survive long enough to enter a cell. Naked mRNA would not have worked.
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 firmly believe that there are thousands of times more species of viruses in circulation that influence human health, almost always in minor fashion, than we currently know. Any random, sub-clinical symptom is in my belief highly likely to be caused by one of such viruses.
That was never a convincing argument, IMO. Just as US institutes would claim that China is responsible, by the same token the argument works on any other lab too - yet the media did not present in that way. Ever. That's not accurate reporting; that's an attempt at victim blaming. Next thing someone may do is give a powerpoint presentation about weapons of mass destruction in some far-away country ...
>Just as US institutes would claim that China is responsible, by the same token the argument works on any other lab too - yet the media did not present in that way. Ever. That's not accurate reporting; that's an attempt at victim blaming.
So your idea of accurate reporting is to apply whataboutisms?
Actually, the US did a lot to downplay the idea that the nearby lab in Wuhan that was doing gain of function research on coronaviruses was in any way involved, to the extent that you'd get shadow-banned on Twitter for mentioning it.
> Scratch your head and you’ll release DNA-rich cellular material into the air. There, it will mingle with DNA from myriad other sources: your own and others’ exhalations and exfoliations, fragments of hair, feathers, excrement, pollen and spores, and microorganisms such as viruses and microalgae. This DNA, which can include segments that are tens of thousands of base pairs long, will then wander the air for perhaps a few days, often clinging to dust particles. It can travel distances that range from a few metres to several thousand.
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.
Probability seems to be one of those things humans habitually mess-up at.
"The chances of this person's unique DNA showing up at the scene are a zillion to one!"
"What does that really mean when the sample also contains unique DNA for a hundred other people? Did all of them commit the crime as a group?"
Depends on how they're using it. To find an unknown person and prove they were at a scene - yeah you'll have the 100 person's worth of DNA to sort through and then match against a (presently) incomplete DNA database. But if you already have a suspect and need to place them at the scene, if their DNA is one of the 100 then they have shown that.
But we’re they at the scene or did they just bump into someone or something that was there?
That's something that would have to be addressed at the trial by the defense attorney raising challenges.
If the DNA is present, it's present - barring any procedural mistakes by the forensics technicians (mislabeled sample, dirty lab equipment, didn't follow manufacturers instructions, etc). Or deceit by one or more members of the forensics team to implicate the suspect.
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.
four figures these days. fits in your hand. nanopore is a revolution. https://nanoporetech.com/products/sequence/minion
there’s youtubers that have videos about doing this in a home wetlab. very achievable. some amateur soil biologists using this to try and sample microdiversity as the planet… humanifies.
Do you have links to these youtubers? Sounds interesting
Not OP, but The Thought Emporium is a personal favourite. Their name belies the hands-on nature of their videos.
https://www.youtube.com/watch?v=F0_q-fD_lyU
Ex-Nanopore employee here. One interesting thing we heard about internally was that OceanX[0] has one of our GridION[1] devices (slightly larger, and built-in compute) that they were using to track whales in the ocean by sequencing DNA found in seawater. Really cool.
[0] https://en.wikipedia.org/wiki/OceanX
[1] https://nanoporetech.com/products/sequence/gridion
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.
> Some people still dispute it
I particularly like this Futurama clip on the subject. https://m.youtube.com/watch?v=VzGtk7Ip4NU
> birds are dinosaurs
Not that I doubt that, but how does DNA help, when we have no DNA samples from dinosaurs?
https://www.syfy.com/syfy-wire/scientists-discover-well-pres...
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.
What a wonderful title, a breath of fresh air.
A breath of fresh _DNA_
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.
> This always blows my mind. We are currently breathing in the DNA of the trees,
At this time of year, believe me, I am aware of the inhaled tree DNA setting off my pollen allergies.
"Soup" is a good word. Pieces of DNA resulting from destruction by nucleases and other enzymes.
The immune system destroy all the DNA in unexpected places in case it's a https://en.wikipedia.org/wiki/Viroid or something. Better safe than sorry.
One of the important steps in mRNA vaccines was to surround the mRNA with a lipid to ensure it can survive long enough to enter a cell. Naked mRNA would not have worked.
Let's wait for smartphones with nanopores
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 firmly believe that there are thousands of times more species of viruses in circulation that influence human health, almost always in minor fashion, than we currently know. Any random, sub-clinical symptom is in my belief highly likely to be caused by one of such viruses.
Yeah, there's just so many microorganisms (and some evolve so quickly) it would basically be impossible to really enumerate the species.
[stub for offtopicness]
As is the Ocean.
Cool.
I think they had to delete all the sequencing data from the Wuhan Institute of Virology so stuff in the air wouldn't show up.
That was never a convincing argument, IMO. Just as US institutes would claim that China is responsible, by the same token the argument works on any other lab too - yet the media did not present in that way. Ever. That's not accurate reporting; that's an attempt at victim blaming. Next thing someone may do is give a powerpoint presentation about weapons of mass destruction in some far-away country ...
So your idea of accurate reporting is to apply whataboutisms?
Actually, the US did a lot to downplay the idea that the nearby lab in Wuhan that was doing gain of function research on coronaviruses was in any way involved, to the extent that you'd get shadow-banned on Twitter for mentioning it.
[flagged]
Why is nature suddenly click bait - changing times I guess.
> Scratch your head and you’ll release DNA-rich cellular material into the air. There, it will mingle with DNA from myriad other sources: your own and others’ exhalations and exfoliations, fragments of hair, feathers, excrement, pollen and spores, and microorganisms such as viruses and microalgae. This DNA, which can include segments that are tens of thousands of base pairs long, will then wander the air for perhaps a few days, often clinging to dust particles. It can travel distances that range from a few metres to several thousand.