“I’m gonna do it on purpose forever,” you said.

March 12, 2025 8:52 AM

elodieunderglass (previously quoted on MeFi) and derinthescarletpescatarian wrote a moving, funny composite narrative about human biology: “Wait a minute,” you say a couple of generations later, because you’re not actually a small animal but an evolutionary process personified and simplified to the point of dangerous inaccuracy for the purposes of a Tumblr post... That link won't work well unless you're logged into Tumblr, so here's a repost that everyone should be able to read.
posted by brainwane (21 comments total)

I just love the ending:

“My inner ocean is such a perfect homage to the primordial soup that I can personally cook up an entire live hairy mammal in it. And then generate excess blood byproduct from my body and give it to the small mammal until it gets big.”

That is an absolutely bonkers pitch, by the way, and everyone thought you were a showoff, even before the opposable thumbs. When the winter came, and the winter of winters, and the rain was acid and the air was poison on the tender shells of their eggs and choked the children in the shells; when the plants turned to poison, and the ocean turned against you all; when the climate changed, and the world’s children fell to shadow; your internal ocean was it that held true. A bet laid against the changing fates, a bet laid by a small beast against climate and geography and the forces of outer space, that you won. The dinosaurs fell and the pterosaurs fell and the marine reptiles dwindled, and you, furthest-child, least-looked-for, long-range-spaceship, held hope internally at 37.5 degrees. Which is another thing that humans do, sometimes.

posted by brainwane at 8:55 AM on March 12 [8 favorites]

Haha I knew this was gallusrostromegalus before I even clicked!

(I mean in that grm is kind of a filter that traps exactly stuff like this)
posted by toodleydoodley at 9:10 AM on March 12 [1 favorite]

I know some folks who do science writing/outreach, and I think of this kind of tumblr post as the best kind of science writing. Poetic, impassioned, weird.
posted by Lawn Beaver at 9:35 AM on March 12 [6 favorites]

Its like someone put my hour long stoned internal monologue to paper. Brilliant.
posted by ianhorse at 9:58 AM on March 12 [1 favorite]

Lovely. Thanks for sharing!
posted by eirias at 10:52 AM on March 12 [1 favorite]

giant bag of seawater

MeFi handle up for grabs!
posted by Hairy Lobster at 11:23 AM on March 12 [3 favorites]

I can't decide between that and and an unnecessarily splashy direction. Or possibly breathing oxygen in a complicated matter....
posted by Greg_Ace at 11:48 AM on March 12

Oh my gosh I love this.
posted by Vatnesine at 11:49 AM on March 12 [1 favorite]

Wait, wait, I'm gonna go with excessively, flamboyantly wet internally!
posted by Greg_Ace at 11:50 AM on March 12 [1 favorite]

On a less silly note:

(Note: the majority of fish, freshwater and saltwater, have a fairly narrow band of salinities they can live in. Every fish doesn’t get to deal with every level of salinity; they are evolved to regulate within specific bands.)

I'm curious exactly how salmon and trout manage to differ from this.
posted by Greg_Ace at 11:51 AM on March 12

an intelligent bag for carrying and regulating a small amount of imitation seawater

Finally - my life has a Purpose, a Reason! Screw you, religion!!
posted by Greg_Ace at 11:52 AM on March 12

c.f. "ugly giant bags of mostly water"
posted by mhum at 12:48 PM on March 12 [1 favorite]

> how salmon

Look up doi:10.1242/jeb.37.2.425 as a starting point from an evolution standpoint, perhaps, though I imagine there’s better summaries than a full paper.
posted by Callisto Prime at 1:30 PM on March 12

Yeah, my attention span on that topic doesn't exceed a quick précis... I was just mildly curious what sort of mechanism or evolutionary quirk allowed them to move between salt and fresh water, such as when spawning.
posted by Greg_Ace at 1:58 PM on March 12

> Greg_Ace: "I was just mildly curious what sort of mechanism or evolutionary quirk allowed them to move between salt and fresh water, such as when spawning."

I'm no expert but some cursory googling indicates that there's a pump-like mechanism at the cellular level in their gills that can both pump sodium ions into and out of their body. They also have other adaptations that involve changing the amounts of water they ingest and excrete whether in freshwater or saltwater in order to maintain the correct balance of ions in their body.
posted by mhum at 2:10 PM on March 12 [2 favorites]

It's like someone put my hour long stoned internal monologue to paper.

Your inner homunculus strumming the twisted strings of your DNA and singing 'The Everliving Mammaloving Evolution-Talking Blues'.
posted by jamjam at 3:45 PM on March 12 [1 favorite]

this is good

oK also it salinitysnipes me hard whenever anybody does the "bags of seawater" because human blood and lymph are not at all like seawater.

They're roughly one third as salty as seawater.

They're closer to freshwater than they are to seawater.
posted by away for regrooving at 7:31 PM on March 12 [2 favorites]

Salmon: To colonize freshwater, saltwater fish developed osmoregulation. Their insides are saltier than the outside water, they need to be able to excrete excess water and keep the salts inside.

Likely this started with diadromous fish that spent most time in saltwater with forays into fresher water for food, safe spawning, whatever. The less salty the water you spend more time in, the better your osmoregulation must be.

Now we have diadromous fish that are born in salt water and can later live in fresh water (catadromous) or that are born in freshwater and can later live in saltwater (anadromous) like salmon.

The ones I find awesome are cetaceans. They go to all the trouble to develop spinal chords, jaws, osmoegulation, lobbed fins, legs, crawled out to land, did everything in the OP, then said fuck it and went back to the ocean, where they are just a big fucking inflated fat balloon (inflatable donut?) keeping the inside sea water separate from the perfectly good outside sea water. Breathing oxygen in a complicated matter.

If you need and are able to separate the man from the work, I really seriously recommend Dawkin’s The Ancestors Tale. There’s been 20 years of advances since it was published, branches of the tree of life have been since pruned, merged, and grafted, but the story is still very good.
posted by Dr. Curare at 8:35 PM on March 12 [4 favorites]

They're roughly one third as salty as seawater.

As I understand it, the lobbed fin fish from which mammals, via tetrapods, descend were most likely fresh or brackish water fish.

So yeah, more like “bags of swamp water” or “mangrove water”.
posted by Dr. Curare at 8:40 PM on March 12 [3 favorites]

Can confirm brackish water is deliciously human. I’ve been swimming in Juniper Spring in Ocala National Forest, and the water is beautifully clear, and you can open your eyes with no sensation of opening your eyes underwater. No saltwater burn; no freshwater sting. Feels like cool air.
posted by toodleydoodley at 9:14 AM on March 14 [3 favorites]

Can confirm brackish water is deliciously human

What?! That sounds amazing and makes sense to anyone who has added salt packets to water before snorting it up your nose. Why have I never heard of this before?

I assume there is some depressing hygiene-related reason that swimming pools aren't filled with this stuff?
posted by straight at 8:32 AM on March 15