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Comment by jasdi | Hacker News Reader

Animal domestication is really wild. So we first select for neoteny (playfulness, dependency on caregiver, physical features people like) basically prolonging the juvenile state. Then we put them in controlled environments of abundance, were all their needs are met. Which further diminishes need to reach adult state (with traits like aggressiveness to compete for resources). This abundance causes them to mature/breed earlier and reproduce more than in the wild. Basically a population of children that can produce children. Then we want this population of children to live longer.

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Recently I had an interesting thought that basically people did almost the same to themselves spontaneously through culture. Which might influence various aspects of human behavior, like social interactions in general, cooperation and means of competition, mate selection. We might have genetic changes that are not maladaptive only in the culture that introduced them. As technology forces culture to evolve it might turn out that huge swaths of human species have their evolutionary fitness suddenly reduced.

Visually humans have neotenistic characteristics compared to other primates, so this is quite plausible.

And mentally. We never stop playing.

Note the popularity of memes about "adulting".

What's interesting is that rigid culture that forced us to do adult behaviors despite retaining juvenile traits, now when it's getting lifted and replaced with freedom to do whatever you please might leave many individuals maladapted from the evolutionary standpoint to prolonging their genetic line. Which I think is perfectly fine. New generations that are better adapted to the culture of hi-tech freedom will arise from the few that currently accidentally already do the evolutionarily correct thing.

> New generations that are better adapted to the culture of hi-tech freedom will arise from the few that currently accidentally already do the evolutionarily correct thing.

That's one possibility. Another is subcultures which prioritise reproduction over personal freedom will end up demographically dominant in the long-run. Look for example at Kiryas Joel, New York, and similar ultra-Orthodox Jewish communities, whose growth shows no signs of slowing down in the foreseeable future. Of course, exponential growth can't last forever, but nobody knows what exactly the limit is and when it will be reached – it might not be reached until they've become a very substantial percentage of the population, maybe even the majority.

> And mentally. We never stop playing.

Do animals stop? There are plenty of examples of play in adult animals:

- https://www.sciencedirect.com/science/article/abs/pii/S03766...

- https://medium.com/illumination/wild-animals-at-play-982e26e...

- https://psycnet.apa.org/record/1998-07899-003

My elder female dog loves to play and the way in which she plays has only gotten more nuanced over time. She's even adapted to play with me, play with other dogs, play with smaller dogs, and play with puppies.

The basic semantics of her language of play are all the same: she bows, she'll yawn, she barks and does that side-eye glance. Sometimes she'll dance. If she gets really hyped up she'll get the zoomies.

Dogs, from what I've observed, are incredibly intelligent and social animals as they exist today.

A lot of dog play is rehearsing hunting-related behaviours. For example, playing tug-of-war over a toy is practising playing tug-of-war over the kill, which helps to break it up into manageable portions. I wonder if adult domestic dogs are more prone to play because they have limited opportunities to use these natural instincts for real? Maybe in a pack of wild dogs where they are constantly being used for real, they would be less likely to rehearse them

>Recently I had an interesting thought that basically people did almost the same to themselves spontaneously through culture.

I think this already well known in evolutionary biology circles though not through culture. I don't recollect but it was most likely Robin Dunbar who said it, people ganging together to kill of the most annoying/bullying/maladjusted members.

It's not really about killing maladapted. In each generation of humans more than 10% of them don't pass their genes to next generation. From the point of view of evolution it is as if they got killed young. Mate selection is way stronger mechanism of evolution then plain survival.

>It's not really about killing maladapted.

I'm sure I did not misunderstand Robin Dunbar, He actually said homicides were common. If a bunch of people hated someone they ganged up and killed him/her, leading to humans being relatively more neotenistic than other primates.

(I used maladapted in a very loose way: especially being maladapted socially, we are not talking about being maladapted phicially and other ways)

Although humans may be reaching reproductive age faster, aren't we generally reproducing later in life? That seems counter to the OPs point.

Those two are naturally related. If getting pregnant at 10 usually lead to death, then your genes will avoid that if getting pregnant at 10 is common.

However if socially we prevent girls from getting pregnant at 10 then biology can make them go through puberty at 10 without risk, since they will not get pregnant anyway.

Edit: As for the playfulness point, for us humans we punish kids for being playful when they reach 7, so it makes sense that we will evolve to stop playing around at 7 and hence becoming adults already by then. We don't punish pets for being playful though, at least not today.

I'm finding it hard to understand your point or not finding that argument particularly convincing. We can socially change much faster than we can biologically evolve. Meaning, the change in birth age can be heavily influenced by social factors (birth control, resource abundance, requirements for self-sustainment in adulthood) much faster than biology would adapt. We can be extremely socially different than those who lived when it was the norm to be pregnant at 14 while being essentially biologically identical.

Further, we can have multi-modal distributions that undermine the biological assumption. Some groups show much lower birth ages because it's not culturally disadvantageous than other groups. In that context, even if the average age increases, it doesn't mean lower birth age is biologically disadvantageous.

>humans we punish kids for being playful when they reach 7

This needs a citation or at least a definition of what is meant by "playfulness", because I find it hard to believe. I don't know any parents who would want their child to stop playing at 7 years old.

> I don't know any parents who would want their child to stop playing at 7 years old.

Parents don't decide what happens to the kids at school though.

> We can socially change much faster than we can biologically evolve.

If the genes were always there but they died constantly 200 years ago it just meant that we no longer cull those people early, and after a couple of such generations we now have them around. Early puberty is still not common, it just exists, that makes it more likely to be biological than social, if the social changes did it then early puberty would be the norm today rather than a very rare exception.

Just like the Eloi!

> evolutionary fitness

But there's no such thing as an objective "evolutionary fitness". It only makes sense to speak of evolutionary fitness in a given niche.

Yes. And this niche moves as culture evolves.

"Animal domestication is really wild"

Dogs domesticated us. Wolves are hunted but dogs a fed, given shelter, love and access to medical care.

You'll let me know the next time you'll have to require the permission of your dog to pee, or when it can trigger surgery to cut your balls or put you down.

That humans are dominant doesn't preclude us having co-evolved.

Co-evolved is a very different word than domesticated.

> neoteny

What domesticated animals were bread for "cuteness"? Cats are mice hunters. Most popular dog breeds were selected for killing and dog fight! That "big smile" is not for laughter, but to crush bones!

And many domesticated animals can not even reproduce without human assistance. How they would survive in wild?

I think requiring human assistance and inability to survive in the wild are an effect of neoteny.

> What domesticated animals were bread for "cuteness"?

Dogs.

> Cats are mice hunters

Cats blur the line between domestication and taming.

> Most popular dog breeds were selected for killing and dog fight

One can breed for more than one thing. (Dog fighting as a selection pressure is very modern and very limited.)

Dogs literally evolved a muscle to make them more appealing to (and help them communicate with) humans [1].

> many domesticated animals can not even reproduce without human assistance

Not an argument against neateny.

[1] https://www.smithsonianmag.com/smart-news/dogs-have-special-...

Dog fighting is limited, but most dog breeds have been bred primarily for a specific practical purpose.

> Dogs literally evolved a muscle to make them more appealing to (and help them communicate with) humans

Not necessarily exactly cuteness. The other explanation suggested is better communication in general - by exposing the whites of their eyes we can see what they are looking at, which is an important cue for humans (we use it between ourselves too) to indicate the direction of attention.

> most dog breeds have been bred primarily for a specific practical purpose

Sure. But most of those traits are shallow. Let the breed go stray and many characteristics go away. The neoteny does not.

> Not necessarily exactly cuteness

The neoteny—large eyes and heads, for example—is precisely cuteness. Not all breeds are equally neotenic. But they’re very much not wolves.

> Sure. But most of those traits are shallow. Let the breed go stray and many characteristics go away.

A lot of characteristics seem to be bred in and instinctive - breed specific behaviour occurs without training. Strays do not breed pure so of course breed specific characteristics are lost.

> The neoteny—large eyes and heads, for example—is precisely cuteness

To an extent yes. The specific trait mentioned in the comment I was replying to was not neotenous. Not all neotonous traits are physically cute.

> breed specific behaviour occurs without training. Strays do not breed pure so of course breed specific characteristics are lost

My point is neoteny almost isn’t breed specific. Let strays breed and it’s preserved—stray dogs are cuter than wolves.

Wild dogs don’t become wolves. (They also stop being French bulldogs.)

> Not all neotonous traits are physically cute

Almost all physically-cute traits are neutenous.

> Dogs literally evolved a muscle to make them more appealing to (and help them communicate with) humans [1].

This scene from an 1953 Tom and Jerry of Spike teaching Tyke what it means to be a dog seems prescient: https://youtu.be/jnW48TihBR0?t=50s

Chihuahua.

> What domesticated animals were bread for "cuteness"?

Fairly recent experiments with domestication of foxes show how it might work.

What you select for is behavior. Mainly you breed individuals that neither attack humans nor run away from them. Any other response than aggression or fear is ok. In few generations it turns out individuals selected this way retain more and more juvenile traits.

I think cats never needed to get domesticated because reacting to humans with neither aggression nor fear is within natural range of perfectly normal behaviors of most individuals of this specific niche feline species that got globalized through its relationship with humans.

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