Spider webs capture environmental DNA from terrestrial vertebrates | Hacker News Reader

Spider webs capture environmental DNA from terrestrial vertebrates

cell.com

106 pointssohkamyung33 comments

Neat! A segment on this was on my local NPR yesterday.

As noted in the article, the aim is to boost (chronically underfunded and logistically challenging) biodiversity studies.

>> With only trace amounts of DNA needed to identify species, the data obtained have the ability to strengthen biodiversity assessments through improving the detection and monitoring of rare, cryptic, or protected species, increasing the taxonomic resolution of biodiversity surveys, allowing for increased sampling of inhospitable or challenging environments to survey, and aiding in the early detection of invasive species.

Critically, they just used a plastic stick to collect webs. So pretty cost-effective!

Looks like UV plays a major degrading role, so sunlight-shielded webs yielded the best results. Which makes sense, because DNA.

Tangent: this could potentially be used to surveil humans in sensitive areas, such as banks. If humans shed enough DNA via exfoliation and breathing, you could capture DNA and process it in the event of a robbery. eDNA surveillance could become a valuable tool in heavy crime areas.

It could possibly also be used to surveil humans more nefariously, though. IIRC, I think this was a plot point of GATTACA.

You can already do this by sampling the air, no spiderweb needed.

https://www.science.org/content/article/dna-pulled-thin-air-...

I'd be shocked if this isn't done already? It was a plot device in the Ben Affleck bank robbery movie where they foiled the police DNA swabs with hair clippings from the barber shop.

Oh! Reminds me of my favorite Sci-Fi ever: https://en.wikipedia.org/wiki/Children_of_Time_(novel)

I’m on the third book of The Final Architecture Series and it’s great space opera with good story-telling. The world of the series feels real and yet mysterious and fantastical.

I looked into his other series when I discovered him and was hesitant to get invested in Children of Time because the reviews I read were mixed and many said it was (paraphrasing here) good but something of a slog.

What do you love about it, and—if you’ve read them—how does it compare to TFA series?

Spider Civilization.

I like TFA a lot, but it is very character driven. CoT is a collectivist story, the non-human-centric story reads like David Attenborough is narrating it. I like that part a lot.

The human/character driven parts of the story feel a bit tacked-on and not actually critical to the themes and messages of the story.

I think it is worth a read, and the sequels are more character driven than CoT.

Maybe I was hallucinatung more detail than was there, but I found parts of the book had stunning parallels between the themes of each storyline, where the symbolic struggles by each cast of characters informed or reflected somehow the struggles of the other.

Hey, thanks for the response. This helps.

Children of Time series a slog? Wow. It’s a page turning spine tingling, rip roarer. Stuffed full of high concepts, great characters and wry humour.

As is the second book. Which kind of adds a horror slant.

The third book is more ambitious and conceptual and in parts, slightly harder going. Still highly rewarding.

Best hardish SF series I’ve read in recent years.

I read it after reading a comment like yours. I read a lot of sci-fi. I wish I had my time back.

I'd advise other people-- if you don't like the first book, don't bother with the rest. It isn't one of those series that is a slog for the first but gets great. You'll like it or you won't.

I like this book but the human parts suck!! I just wanna read about spiders. Not about some people on a ship.

True, but the dysfunctional humans give much needed context!

And Kern - arguably human, at some point in the narrative - is one of my all-time favorite characters.

The Barbie Movie was huge right?

But I would love to see a feminist movie made from "Children of Time". Female Spider society

Where the Female Spiders rule, and eat the men.

And casually talk to each other like "you feel like going to hunt some men tonight", and literally eat them.

Also great for surveillance of human mammals, especially for knowing which ones frequent which areas. That is assuming you already have their DNA for comparison. Or no? Would this work?

Probably not, DNA degrades relatively quickly in uncontrolled conditions, so the unique markers of an individual human would probably be hard to grab from a dust particle suspended on a spider web. This works for detecting different species, not necessarily individuals.

Plus, there are infinitely easier ways of surveilling humans, like just watching where their GPS tracked phones go.

There are also easier ways of tracking humans via DNA - we're literally shedding genetic material with every step, on everything we touch. Skin flakes here, saliva there, etc.

And all of that is dispersed in the air that you could theoretically collect and sample in your hvac system.

So I guess the cyberpunk equivalent of TFA: disassembling a router, wireless phone charger, or any of the countless devices equipped with a tiny cooling fan, that increasingly live among us in our homes and offices, in order to sample DNA from the dust that accumulates on the fan blades.

(To add a little insult to injury: pull it off an air quality monitor. Those PM sensors have a neat, tiny, dust-moving fan.)

> DNA degrades relatively quickly in uncontrolled conditions

Alternatively, it hangs around for millions of years.

https://www.nhm.ac.uk/discover/news/2022/december/worlds-old...

Yes it works for mammals too. It works with just a vacuum even outdoors.

https://www.science.org/content/article/dna-pulled-thin-air-...

there's a cool preprint from a few weeks ago where they sequenced a collection of 34 years worth of air-filters in Sweden: lots of mammals! eDNA, just from air. https://www.biorxiv.org/content/10.1101/2023.12.06.569882v1

Up to ~35% of the detected DNA was human (Fig S5)

Kept on a zoo enclosure. This point is important IMAO.

> Webs from woodland and zoo show eDNA from native and non-native fauna, respectively

It does not matter, the effect on the enclosure is the problem.

They compared a web found in native woodlands to a web in a zoo enclosure to demonstrate the potential to detect local animal populations. The zoo had more species because it's a zoo. They didn't limit the study to only zoo-bound webs as you seem to be suggesting.

This will be really neat when we have Spide-Spun-Space-Sensors whereby a planet it cluster-bombed with sensor-balls with a special spider-silk-style web which can grab DNA, but onboard sequence it... and report back to the orbiting drone before self destruction.

You can just vacuum and filter the air for dna

Wow, crime scene DNA-Devil: Here is a simple attempt at an sensor gun to dirt-devil up crimescene DNA powered by SyDNAr sensors (TM):

https://i.imgur.com/kkxhEqJ.jpg

https://i.imgur.com/aMk7UfM.jpg

:-)

I was curious about the use of "terrestial", and it looks like it means "not aquatic" rather than "not from outer space".

i think terrestrial would mean earthly. from the latin root, terra, for earth. from space is extra-terrestrial. But then greek is geo, or gaio like gaia. but we dont call aliens super-gaians. I dont know where im going with this. Language is messy. English doesnt include every version of every root. We do have subterranian though. Superterranian?

We've sent spiders to space[0] (honestly, it's like we _want_ a horror movie to play out). But who knows - maybe one day we'll get DNA from extraterrestrials.

[0] https://www.si.edu/newsdesk/releases/world-s-first-spidernau...

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