Pooping hippos create ‘community guts’ in African ponds | Hacker News Reader

Pooping hippos create ‘community guts’ in African ponds

science.org

94 pointsrbanffy36 comments

> The bacteria that live in our guts influence everything from nutrition to autism.

You might think an article in Science could manage to avoid a deeply misleading falsehood before completing its very first sentence.

Despite some statistical correlations and mouse studies, the idea that gut bacteria influence autism in humans is poorly supported. And recent studies suggest the influence may go in the other direction. [1]

Just keep in mind that "top" journals like Science, Nature, and PNAS have a tendency to publish flimsy ideas if the result is sensational. They are the tabloids of science and must be taken with a hefty pinch of salt.

[1] https://cosmosmagazine.com/health/body-and-mind/autism-gut-m...

It's an active area of investigation, and you're right that there's yo-yoing. But note that the article discussed in your ref is published in Cell, the same journal that also published some of the original work it's refuting. As much as NatSciCell publish sensationalized work, high impact work pretty much universally gets published there still.

It's like the nytimes. Popular to crap on it, but in the end they still put out good journalism.

I'm surprised an article on hippo poop altering the local environment doesn't mention the unique (and disgusting!) way that hippos poop: by spraying it everywhere propeller-style with their tails! The usual explanation for that is that it's to mark their territory, but I wonder if this offers a more cooperative explanation? (I would be skeptical of that explanation TBC.)

It may be disgusting, but it makes for a great effect when played in reverse: https://www.youtube.com/watch?v=v5SSnQBtaq4 :-)

what's with the blurring in that video?

To prevent it from being flagged as for mature audiences and potentially getting a strike on the channel. Showing fecal matter in high, up-close detail would mark it as a "V" rating (violence/disturbing)[0]:

> Examples include real or dramatized medical footage, or depictions of disgusting or scary content in a horror or fantasy context.

[0] https://support.google.com/youtube/answer/146399

But this is not a horror or fantasy context, it’s an educational context. Am I missing something?

Youtube doesn't care about that. At least, content creators don't generally take that chance. There is very little recourse if Youtube decides your content violates their rules.

That was from the "mild" section, too. Looking at the more extreme bullet point for the same rating, there's

> It may also include pervasive imagery or situations that are disturbing or repulsive to the average viewer.

Which, given that the entire video is about literal buttholes and feces, probably fits to some degree.

A bit like for fair use in educational contexts, it can approved after a few (?) back and forth with the YouTube moderators, on a per video basis, if the creator is lucky enough to get reviewed by an actual human.

Otherwise the video just gets flagged and there's no recourse.

Turn on the audio, it's to protect the manatee anteater's identity

That was so funny and clever.

It's a spectacular experience if you're lucky enough to see it at the zoo!

Out of luck if you wear glasses.

This comes up in the movie Okja but I didn’t know it was based on a real thing

That's when they do it on land. If you see underwater footage of them there's usually lots of brown grass bits floating around. That's hippo poop too.

For a good time, check out any Casual Geographic video that mentions hippos on YouTube. I did not know they sprayed their fecal matter everywhere, but it fits my expectations of what to expect from a hippo.

Humans display similar outcomes in the Ganges river. But it is dangerous for outside tourists for sure and it seems the locals are immune or inoculated to all the e. coli bacili in the river. The humans there believe the river to be purifying the soul and spirit.

https://en.wikipedia.org/wiki/Ganges

https://www.indiatimes.com/news/india/fatal-bacteria-like-e-...

When I visited Varanasi there were literally bodies and ashes being put in the river right upstream from thousands of people bathing, drinking, playing, and worshipping. Wild.

I was traveling in Rishikesh and there was an enormous pilgrimage for people to visit a temple dedicated to Shiva. I learned of a number of fascinating traditions from the pilgrims.

One was to fill a water bottle with "Ganga Water" to splash onto some hanging fabric at the entrance of the temple.

On the 14km hike up the mountain to the temple I was invited to a chillum circle. As we sat around smoking and talking I saw one of the other people reach down and take a drink from the water bottles so many people had hanging from their belts.

I asked, "Is that... your Ganga water?"

They responded, "Yes! Would you like some?"

I said, "Thank you, but my body is unfamiliar with drinking Ganga Water. I think it will make me sick."

They replied, "Maybe you are already sick if you are unable to drink Ganga Water."

> If swallowed by other hippos, the bacteria may possibly aid digestion and disease resistance.

Presumably it also aids in the spread of hippo-hosted parasites?

And yet apparently that cost doesn't outweigh the benefits of this behavior.

The hippo isn't the only thing involved here though, the parasites and bacteria are too. So it may not be strictly best for the hippo, it may be best for something else that is able to influence the hippo.

It may mean development of pathogens that that hippo clan is resistant to but which rival hippo clans, or perhaps rival species, are not. Like “Guns, Germs, and Steel” but for hippos.

Lots of behaviours of mammals seem to assist the propagation of parasites. For example sneezing seems to have very little biological need, yet is incredibly good at distribution of airborne pathogens.

The sneeze reflex is complex, and clearly not encoded in the very small and simple viruses that trigger it.

I have a hypothesis that many undiscovered pathogens in fact have a positive impact on survival rates of their host, which is why behaviours that deliberately spread (some) pathogens are so common.

A sneeze is a like a cough in that its a mechanical way to expel blockage and foreign bodies from nasal mucous membranes that happen to be great environments for pathogens to grow.

In general parasites that kill their hosts are failures. That's why every single human pandemic has come from zoonotic parasites. It's parasites that are not adapted to humans and accidentally kill them. Generally, given enough time, they would eventually adapt and the strains that are the least harmful (sometimes even most beneficial) would win out as their hosts would do better and allow the parasites to spread more

This happened in South America with a cholera outbreak. In countries with good sanitation, strains that made their hosts sicker ended up dying out because people had to stay indoors more. So the strains that were less sever allowed people to go out and interact socially and therefore spread the cholera further.

Arguably the same thing might be happening with the Omicron variant which early data suggests is much much milder than previous variants

> Arguably the same thing might be happening with the Omicron variant which early data suggests is much much milder than previous variants

The evolutionary selection pressure that can result in weaker viral variants comes down to the fact that deadlier viral genetics die off in the corpses they create from their hosts, sometimes leaving only the weaker genetics in the hosts that didn't die. That selection pressure really isn't there for any of the COVID variants, especially with its long incubation time. The virus is free to mutate into stronger variants in the mean time.

This article reminded me of a story I heard second hand. In the Karoo of South Africa, sheep farmers provided lambs with feed containing the ground up stomaches of older sheep who lived in the area. If this was not done, then the lambs would fail to thrive when grazing. Presumably the ingested intestines transmit bacteria conferring the ability to digest otherwise indigestible material.

I can tell you first hand that Karoo lamb is perfect. In decades of meat-eating all around the world, I’ve never encountered its equal.

This article pushes the animal-centric narrative, as though hippos are somehow controlling this process. It makes more sense to think of the bacteria as the dominant players in this ecosystem and the hippos (or their intestines and feces) as just one of the channels through which they propagate.

I would think that it's a little of both, and probably a few other players that nobody really noticed yet.

Flanders and Swan's Hippopotamus Song:

https://www.youtube.com/watch?v=4zpDF3Py7r8

>Mud, mud, glorious mud, nothing quite like it for cooling the blood.

just don't tell Gwyneth Paltrow (https://www.iflscience.com/health-and-medicine/gwyneth-paltr...)

Fecal transplants in humans are purported to have a myriad of health benefits. I wonder if the clean water push may actually be harmful in some ways as people lose some diverse, healthy bacteria in our guts?

As far as I know fecal transplants are only known to be beneficial in some cases, presumably when there is something seriously wrong with the recipient's gut biome. It doesn't seem clear to me that clean water is bad or fecal transplants are generally helpful.

Keep in mind that lack of clean water is a _huge_ killer. The benefits would have to be ridiculous for it to be worth it.

Some chronic gastro issues like IBS and Crohn's are virtually unheard of in developing countries. There's a theory that this because people in developed countries have underdeveloped immune systems from underexposure to foodborne bacteria/viruses.

Net-net clean water is definitely more important but there's still some drawbacks.

https://en.wikipedia.org/wiki/Hygiene_hypothesis

In my native country there's a joke/saying that says that kids who ate their own shit as babies have good luck. So if someone tells you you have good luck, their making a joke about you being a shiteater lol.

I've always wondered if this might be rooted in the large number of observed health benefits associated with early childhood exposure to diverse microbiomes

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