What octopus and human brains have in common | Hacker News Reader

What octopus and human brains have in common

mdc-berlin.de

82 pointsyamrzou27 comments

For those lost, the article is largely expanding on just a single sentence:

> octopuses possess a massively expanded repertoire of microRNAs (miRNAs) in their neural tissue – reflecting similar developments that occurred in vertebrates.

Better reading: https://www.science.org/doi/10.1126/sciadv.add9938

It seems like the crux of the discovery is the "expansion of repertoire" of miRNA, and the control group they're comparing to is vertebrates as a whole, and not specifically humans. According to some quick scanning on wikipedia, the importance of miRNA in neural tissues in mice has been shown by knocking out those genes.

I wonder if the implication is that the massive complexity seen in vertebrate neural tissue is dependent on the ability of RNA to edit itself and somehow enable cognitive capabilities far beyond those encoded in the un-edited DNA?

I'm just an enthusiastic layman so take all what I've written with a pail of salt.

Further to this, could some conditions that lead to neurodiversity be the result variations of miRNA expression mechanisms?

usually, this is on octopus. human have more gene can generate more different RNA.

Octopuses are interesting because they are so different from the mammals, yet are somewhat intelligent. The visual system is good but very different. They seem to have a more distributed system than mammals, with more done out in the limbs. More like the way automated factories are built. There's more than one way to do it.

What I find interesting is that as far as we know, they can’t see color and yet they can match their pigmentation to a colored background.

I’ve always wondered if they can blend in against an artificial background, say a checkerboard pattern.

cuttlefish ain't quite octopi, but do i have the video for you:

https://youtu.be/pgDE2DOICuc

spoiler: right angles are not in the repertoire

Somewhat related - if you haven't yet, do see the "My Octopus Teacher" doccie on Netflix. Extraordinary creatures are these.

Alternate title "Assassination Classroom"

That’s funny

All right, this keeps coming up. I’ll put it on the list.

I can recommend “Other Minds” by Peter Godfrey-Smith for a pretty in depth read about octopus intelligence. Fascinating stuff!

Yes, what do they have in common indeed. I didn't quite catch that from that article.

Haven't heard of microRNA before...so this is just random RNA floating around?

The opposite of random may be a better starting point. RNA we think of mainly functions a message from DNA to build protein. but it is not too shocking there are other "messages" or conveniently shaped molecules to aid or inhibit existing cellular processes.

Yet another reason the word "gene" is unsafe to use except in reference to a heritable trait.

So intelligent yet so short-lived.

Their digestive tract fuses shut as sexual maturity

Its a darwinian failure (or success) because it cant be weeded out by selective pressures since it happens after reproduction

Can it be surgically re-opened? To see how much could they really live?

Fascinating thought but I’m afraid of smart organized octopus

We’re lucky they die so young

Haha! It would've been cool to share this planet with another intelligent species. How would we communicate with them?

Could an octopus reproduce a second time if their digestive tract remained open? It seems like an octopus that could breed multiple times would have a selection advantage in the form of more offspring.

> cant be weeded out by selective pressures since it happens after reproduction

if there was a population that didn't starve after sex, they might out-compete a population that did, say, by passing on learned behavior to their offspring

Their offspring are near microscopic and in vast numbers. A behavior mentoring relationship would be hard

Perhaps if they evolved a stage where the tiny things latched onto the parent for protection from being food, and lived off the parent, then the parent might evolve to produce an edible skin (for tiny octopus) and hang around longer

There have been experiments that remove the gland that produces the hormone that kills off octopuses after copulation and birth. The octopuses seemed to live on with no problem, seemingly implying that the early death was indeed an adaptation to make room for the newly born.

How much longer could they live?

4-6 months (nearly 50%) longer.

Elaborating on an earlier point, making room for the newborn after reproduction (via premature death) is evolutionarily advantageous because octopuses are cannibals…

https://www.livescience.com/why-octopus-moms-self-destruct

I don't recall or know how much longer. Upon searching for it now, I couldn't find any information. There were vague allusions to months longer or doubling the lifespan, but those didn't cite anything. I'm not sure of the normal lifespan across the different octopus species, but I seem to recall it's generally around just a couple years. Apparently, removing the optic gland was done all the way back in 1977 by Jerome Wodinsky. I thought it was much more recent than that.

Edit: This video has always stuck with me. A single octopus female was observed guarding her eggs for over four years.

https://www.youtube.com/watch?v=lFCQltYMLQk

They are such deeply interesting creatures.

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