Mapping the Urban Biome

June 5, 2021 10:21 AM

Cities Have Unique Microbial 'Fingerprints' - the DNA on your shoe is likely enough to identify where you live. The three-year analysis turned up thousands of previously unidentified kinds of microorganisms, including almost 11,000 viruses and over 1,300 types of bacteria that didn't match any known species.

Study: A global metagenomic map of urban microbiomes and antimicrobial resistance

Project: MetaSUB

posted by Gyan (11 comments total)

I will never get tired of the constant rediscovery of how relentlessly pervasive life is, and how no matter where you are it’s interconnected ecosystems all the way down.
posted by mhoye at 11:36 AM on June 5, 2021 [6 favorites]

Wasn't something like this in one of the original Sherlock Holmes stories?
posted by praemunire at 1:30 PM on June 5, 2021 [1 favorite]

On a few occasions, although only with reference to geology. Holmes's ability to identify areas of London by knowledge of their soils is part of Watson's initial assessment of his capabilities in A Study in Scarlet, and the list is referred to again in The Five Orange Pips. Holmes demonstrates this specific talent on at least one occasion, deducing, in The Sign of [the] Four that Watson has been at the Wigmore Street post office:

"Observation tells me that you have a little reddish mould adhering to your instep. Just opposite the Wigmore Street Office they have taken up the pavement and thrown up some earth, which lies in such a way that it is difficult to avoid treading in it in entering. The earth is of this peculiar reddish tint which is found, as far as I know, nowhere else in the neighbourhood."

The identity of the perpetrator is in part deduced in The Three Students by Holmes's recognition that the indented ball of putty-like substance on the exam setter's desk is clay from a running track. However, this is perhaps closer to a reversal of his usual trick of deducing minute details from footprints, as much of the clue lies in the shape of the deposit (which has fallen from a spiked running shoe, which has also gashed the desk when hastily removed).
posted by howfar at 2:18 PM on June 5, 2021 [3 favorites]

Not just microbes: Pigeons, too.
posted by adamg at 4:01 PM on June 5, 2021

the DNA on your shoe is likely enough to identify where you live.

So's the phone book.
posted by BWA at 5:12 PM on June 5, 2021 [1 favorite]

I tried putting a phone book on my shoe but it made me walk funny.
posted by howfar at 6:37 PM on June 5, 2021 [3 favorites]

Just opposite the Wigmore Street Office

I was just rereading this chapter, this thread having brought it to mind, and noticed that in the original publication of The Sign of Four in Lippincott's Magazine, Watson tells us that Holmes knew he had been at the Wigmore Street post office, but then tells us that Holmes deduced this with reference to Seymour Street (which is the name of the same thoroughfare east of the intersection with Marylebone Lane). Most subsequent publications (usually under the title of The Sign of the Four) amend this to Wigmore Street.

While it is, of course, possible that the good doctor was confused, or even that Holmes's mind had become clouded by the injection of cocaine he had just taken, I think it more likely that, in particular as Watson was almost certainly still living with Holmes at the time of initial publication (it seems unlikely that Watson and Miss Morstan could have financed their marriage on his limited income prior to this early sale in his distinguished literary career), the two thought it more prudent, given the forces ranged against the great detective, to somewhat obscure the location at which they were accustomed to conduct their correspondence.

Naturally, at the dates of later publications, and particularly with the removal of Professor Moriarty and Colonel Moran from the London scene, such occlusion, which would have offended both the precise temperament of Holmes and the literary sensibilities of his chronicler, became unnecessary and was amended as such.
posted by howfar at 7:20 PM on June 5, 2021 [2 favorites]

I wonder how much of Chicago's unique DNA is traceable to certain hot dog toppings?
posted by Halloween Jack at 9:19 PM on June 5, 2021 [1 favorite]

Good stuff. In 2003-2004, J. Craig "Human Genome" Venter sent his yacht Sorcerer II off on a voyage of discovery to sample the oceanic microbiome [commentary with links]. It transpired that, for all the sweeping currents, different parts of the ocean had quite different microbial communities: I was shaken that it was not stirred. It would be good to re-sample to see how random vs reproducible those findings were: ditto cities.
posted by BobTheScientist at 11:37 PM on June 5, 2021 [1 favorite]

The downside of tropical living is that every surface - street, sidewalk, fence, light pole, house, etc - is a cesspool of CIPRO-resistant staph colonies. The temperatures never get low enough to curtail them, much less sanitize them. I cringe when I see visitors wearing tiny flip-flops, or horrifyingly, going barefoot on these mob-travelled sidewalks.

I would be interested in the biome and microbial analysis; I absolutely refuse to collect the samples.
posted by halfbuckaroo at 8:41 AM on June 6, 2021

I'd really like to see this experiment extended to see if the composition drifts or is steady over the seasons and year over year
posted by Mitheral at 7:55 PM on June 15, 2021