Myelination in cephalopods

Question

I am a complete amateur regarding biology, so please forgive me if this question is a little stupid. Could we ever create squids that have human-level intelligence and could serve as a replacement in case humans die out? I heard that squids can have giant axons, that can exceed 1mm in diameter. However, they do not have myelin coating. What would happen, if we would give their cells myelin coating (by gene editing)? The signal speed in the axon seems to be related to intelligence, but the large axons already compensate for the lack of myelin, so would myelin coating even change anything?

I have no background in biology and recently became fascinated by cephalopods. I would appreciate it very much if anybody with a little more knowledge of the subject could answer these questions. Thank you very much for your time.

Edit: I ask this question here and not on the biology board, because I was told that more "speculative" questions belong on this forum.

Answer 1

While squids do have giant axons only a handful of their millions of axons are so large. These axons control the squid’s siphon which is used to expel water and propel the squid and are used to escape threats. It is thought that the increased axon size and resulting increased speed evolved to make this escape response as fast as possible. The vast majority of the squid’s axons are much smaller and similar sized to our own.

Since our understanding of how brains work at their fundamental level is limited, it's hard to say what effect myelinating squid axons would have. Presumably, it would increase action potential speed which would generally improve the speed of the network as a whole, but whether this increased speed would necessarily translate directly to increased intelligence seems tenuous to me. However, recent work has shown that myelination is also a dynamic process that allows for slowing down and speeding up individual axons which are particularly important for processes that involve precise timing such as hearing but also potentially Hebbian learning.

Answer 2

Octopus and squid are generally solitary creatures, and will fight viciously if confined to the same area. So even if they were super (myelin enhanced) smart but still antisocial, they are probably not going to achieve great things. Cooperation, trade and beer are what made civilization.

However I did hear about an experiment where researchers put MDMA (Ecstasy) into the water of some octopodes. Funnily enough they were much more friendly after that.

Sadly there is not enough MDMA to add to the sea to turn it into one giant rave wave :(

Evolution to the rescue!

What if there was a bay next to some island, where humans regularly (each weekend) consumed certain substances, had a great time, excreted most of it, which eventually made its way into the water; before going back to work for the rest of the week. So the octopodes in the bay cycle between being super happy, hugging, dancing, telling eachother 'I love you sooooo much', and then have the mother of a paranoid downer.

During the downs, the most anti-social get real mean, seeking each other out to settle scores and ripoff each others limbs. (Talk about a bad case of the Mondays!)

This cycling means the slightly more social octopodes get drawn to the weekend parties. While the more antisocial pick fights with each other on the week days; removing themselves from the gene pool. This causes selective breeding for sociability. Before you know it we have smart social cephalopods (with taste for drum and base). What they lack in myelin they make up for in fine digital octal(?) manipulation, mixing sick beats, and mad dancing skills.

Answer 3

Could we ever create squids that have human level intelligence? Well my first impression was I think not, but forever is a long time so I would say maybe. I suspect that the molecular machinery that controls squids is very specific to squids and has evolved over millions of years in the same way that the molecular machinery for humans has evolved to help humans.

But I would be surprised if such as simple change (adding mylin) would produce the effect you are looking for. It would probably require thousands or millions of generations of squid and a huge amount of artificial selection to have the effects that you are after. Perhaps thousands to millions of years (as I said forever is a long time) might provide something of interest.

One key problem is the environment of the squid. Whilst they might become quite smart, water is not the ideal place for intelligence and civilization as we know it to fully develop. For example think how difficult it would be to experiment with chemistry under water or to refine metals.

That said there is scope for squid to become more intelligent, but whether the type or level of intelligence is what you were thinking about is hard to say. You might find this book of interest.

In one chapter a scientist reports capturing a live octopus and keeping it in a tank in his living room to see how it reacted to him and his family on a daily basis. It figured out that it could attract his attention in a number of ways, one way was putting its tentacles into the tank water out let causing the tank to over flow and another was by squirting a water jet at the bulb just above the tank causing it to blow.

In short I believe it would be possible to improve the intelligence of an octopus but it would take a very long time and would not be susceptible to quick fixes. Also the intelligence that resulted might be surprisingly alien to humans, so I doubt it could counted as a human replacement in part due to the nature of the water environment.

Answer 4

I'm going to answer this question from a non-biological perspective, as I think the question you're actually asking is 'Can a Squid be as intelligent as a human?' The supplementary question being 'Can squids function like humans?' This latter question is a mine-field of broad issues so let's deal with the first question first...

In order to answer this question correctly, it is perhaps first necessary to understand what intelligence actually is. In computer science, the definition for intelligence we use is that intelligence is the ability to identify and recognise patterns of varying levels of complexity and completeness.

That is to say, an intelligent creature is able to see connections between things that an unintelligent creature can't, and can see obvious connections faster. This may seem obvious, but this level of precision is important when you consider how often intelligence is conflated with knowledge, awareness, liveness, consciousness, etc. The important point to note is that intelligence by this admittedly narrow definition means that there are already neural networks that are arguably far more intelligent than humans within a narrow domain (neural networks are basically just complex correlation detectors) but that doesn't make them all that 'useful' as human replacements.

Humans have capabilities that are related to intelligence that computers lack; curiosity, drive, contextual awareness. These are just some. So, is it possible that your cephalopods can be made to be as intelligent as humans? Sure. In point of fact, this is already being looked at given some of their demonstrations in the past.

The next question though is whether or not that intelligence can be harnessed in a way that we would deem useful. Believe it or not, humans have a lot of other body configurations that directly support their intelligence that have little to do with the brain. Arguably the opposable thumb (allowing us to be tool users) has contributed a lot to our ability to build intelligence, as has vocal chords (allowing us to share learnings rather than force all to build from scratch). Some cephalopods have dexterous tentacles which might replace the opposable thumb in some regards, but the lack of language is a much larger barrier.

An intelligent creature with which communication is impossible isn't 'useful' as a member of a social society. Certainly, the body of patterns such creatures can call on is limited to their personal experience. Part of what makes humans so intelligent today is that we're not learning our patterns from scratch - we have oral language that allows us to learn from what people tell us, and more importantly we also have written language that allows us to learn from people throughout history that don't need to be present in our immediate vicinity in order to share their own learnings.

The advent of things like the internet has made knowledge even more accessible and is arguably manifested in what we call the Flynn Effect, which is the drift to higher intelligence over time by humans thanks to more accessible knowledge. Being knowledgeable or having access to knowledge doesn't necessarily make one intelligent, but it does act as fuel for intelligence in the form of raw data from which patterns can be identified.

So; your squid and octopus related human analogue is possible, but regardless of the biological considerations, you need to make your species capable of efficiently sharing information and learnings between them at a greatly accelerated rate, and that generally means a language of some form, even if it is a sign language to begin with.

All this said; the way to think about it is this;

1) The Biological structures define the upper bound of how intelligent your creature can be. The neural structures have to be able to process sensory input and integrate it with the existing body of knowledge in real time, and the more that can be done, the more intelligence is possible in your chosen creature.

2) The Environment will define how much of that intelligence will be realised. Part of that may be biological, like the opposable thumb, but ultimately your environment needs to provide a rapid and efficient delivery of existing knowledge on which your intelligent creature can build, laying down learnings on that foundation for the next generation to utilise in their own turn.

If you provide for both of those things, then your cephalopods have a chance at realising the massive potential you are setting for them.