> 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?

> 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

> 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.

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

Chihuahua.