Italian bears living near villages have evolved to be smaller and less agressive | Hacker News Reader

Italian bears living near villages have evolved to be smaller and less agressive

phys.org

The selective pressure of a .338 Winchester Magnum, is not to be underestimated.

Funny thing is something similar occurs in lab mice. Where a technician is selecting a mouse for cull the more aggressive mice are more likely to be the ones selected. Problem mice who kill their littermates can ruin experiments.

same with russian fox fur breeders. i don't remember the numbers, but after a surprisingly small number of generations the foxes turned into cat-like pets.

Yes, that's a quite famous experiment, and still ongoing. Similar effects of "domestication syndrome" have recently been reported in wild urban foxes and raccoons.

Remember reading something about humans themselves show the signs of domestication syndrome.

Not in the literal sense (which would semantically impossible), but we have domesticated ourselves with the advent of farming and the domestication of crop plants. We fundamentally changed our own lifestyle into an agricultural one, the same we changed lifestyle of several large mammal species to co-exist with us in that agricultural lifestyle. So perhaps in some sense, maybe we actually did literally domesticated ourselves.

Wheat, barley and similar plant life have done pretty well for themselves, perhaps they domesticated us?

A chicken is an egg’s way of making more eggs.

The markers of domestication in modern humans long predate the farming. 'Human' was the first animal available for domestication. There is a distinction between the domestication as set of changes in the organism and the 'applied' domestication in farming. In the applied sense, the humans on the top of the hierarchy do actually farm the humans below them.

> Not in the literal sense (which would semantically impossible)

Why is it impossible the humans are not domesticated? Are you making a point about language?

I think this is certainly true. People in cities, where there are high amounts of people around act differently when they are in a small village or in nature with fewer or no people around.

Executing murderers will change the population over a few centuries.

Yes, executioners do proliferate this way. They tend to run out of murderers quickly though, then use any other excuses to execute.

Only if they haven't yet reproduced.

I doubt it. The fraction of population that is murderers is quite small.

If so, you don't have to execute a lot of them to affect the murder rates!

The question wasn't changing the murder rate now, but changing "the population over a few centuries". If it doesn't change the population genetics significantly it won't do that.

If 1% of men are potential murderers, and we execute 10% of them in each generation, it will have huge a impact on the murder rate over a few centuries, even though not a lot of people got executed, and the overall genetics of the population hasn't changed much.

Well, no, that presumes "murderosity" is due to rare genes concentrated in murderers, not unfortunate combinations of genes widely spread in the population. Experience with "disease genes" has been they mostly of the latter type, with each gene having a minor effect.

The rate of the effect is probably unknowable. I think we agree that it exists.

It is now. OTOH I have read that an estimated 1/4 of male chimpanzees die at the hands of other chimps (whether murder or war). So it’s not implausible.

Tails curled, ears drooped and they became mostly white.

It wasn't for fur, they ran a long-term selective breeding experiment just to see if they can pull it off.

Do lab mice breed after selection for experiments?

What portion of lab mice are from genetically stable inbred lines? I assumed most of them were from those lines due to their predictable characteristics. C57BL/6 being predictably kind of bitey for example

What is interesting is it is happening with urban racoons too. I'm not sure what the selective pressure might be for smaller snouts. I don't think racoons are being killed like a dangerous bear might. I'd assume if any are being actively fed for looking cute it is very few of them, and those doing the feeding wouldn't be selective about it.

My best guess is that the short snout trait is in linkage with something else that is actually what is being selected upon. At least for racoons.

https://www.scientificamerican.com/article/raccoons-are-show...

One evolutionary pressure that exists in city raccoons is being run over by cars. Others might be access to food, which cute (and less aggressive) raccoons might have an easier time with

My guess would be a linkage with something else as you say. Look for example at the Russian domestication of silver foxes which was done very deliberately, and bred for less aggressiveness, yet it caused physical changes in appearance like dog-like ears and tails: https://en.wikipedia.org/wiki/Domesticated_silver_fox

I heard the same process has been running on humans for the last few millennia. Apparently 2% of the population was executed every year, wherein presumably the most aggressive and independently-minded individuals are overrepresented.

Something something autodomestication...

Wouldn’t the ones doing the executing be the most aggressive?

It's just a job, and the decision is backed by justice.

The guy who kills a family for fun is more aggressive than the guy who execute him. I'm not even sure how you could get to any other conclusion

In that scenario, the guy who kills a family is also an executioner. But in the context of a world where 2% of the population is executed every year, presumably that is one without much of a justice system, and more of a dictatorship (where the dictator and their underlings are pretty aggressive).

Edit: I think "most aggressive and independently-minded individuals" needs to be defined further, because, obviously, a human without a tribe isn't going to survive long, but also no tribe wants an unpredictable wildcard. So one can be aggressive, with long term strategic thinking, but also not impulsive so as to become persona non grata.

An aggressive, long term thinking individual (or group) can cull other "aggressive and independently-minded individuals" so they don't develop into threats.

> the guy who kills a family is also an executioner

Quite literally not... "executioner: an official who effects a sentence of capital punishment on a condemned person". An executioner is someone who is legally allowed to give death as a consequence of a judicial decision, not simply someone who kills.

Words have meaning an homicide isn't a murder, a murder isn't an execution, &c.

No, they are not. I think, on average, those who execute are much less aggressive than those who are executed.

https://en.wikipedia.org/wiki/List_of_countries_by_mortality...

Even in warring countries, or countries without much rule of law, death rates (from all causes) is ~1.1%. Let's say good data is not available, and the real figure is double or triple that number.

An annual death rate of 2% just from executions would be in a society with a super aggressive dictator (or faction, I guess).

For more context, annual WW2 death rates over 5 or 6 years were not as high as 2% per year. Only Poland seems to have been higher.

https://en.wikipedia.org/wiki/World_War_II_casualties

I look at aggression as an emotional state, rather than the capacity for violence. Consider the army. Soldiers are expected to commit violent acts on enemy soldiers, yet they are also expected to maintain emotional control. They are typically expected to avoid killing civilians. They are certainly expected to avoid killing friendly targets. Clearly they have a capacity to commit violence and I suppose most people would say there is a need for aggression because of that. On the other hand, they are not aggressive in the sense of random acts of violence (as would be the case of a bear or a raccoon attacking a bystander).

Every year, or every generation? I could believe 2% per generation.

Makes sense. The more aggressive bears would be more likely to get in fights with humans, which generally turns out badly for the bear, either immediately or from being subsequently hunted down. OTOH, more cooperative bears will more likely be tolerated and even fed, like this bear (different population) who started out as a nuisance to the beekeeper[0] and now is an 'official' taste tester.

[0] https://time.com/5664393/bear-beekeeper-video/

The legend says that after few generations, the bears developped a taste for high quality pasta.

They also refuse to eat in the trash bins of anybody that drink Cappuccino after 01:00pm in a sign of integration.

Next step, they start speaking in an Italian accent, like this husky: https://m.youtube.com/shorts/Roc5WV-gBAY

or worse, till we breed softer claws, speaking with their hands

soon they'll be helping nonas with the focaccia

Well, that region already has a kind of cake called "bear bread" (Pan dell'orso) so it's only fair bears start to make it.

Not just bears it seems: https://www.scientificamerican.com/article/raccoons-are-show...

Coyotes are on their way too

Upcoming: Selective pressure of AI coevolution leads to humans with a fear of unplugging things and the ability to sleep while sitting.

Like wolves that evolved into dogs. Interesting.

Isn't it a little too fast for "evolution"?

Not really?

If there's a range of "how aggressive a bear can be", and it's mostly driven by genetics, and aggression is heavily selected against in the environment? Then you can get a considerable reduction in aggression in the span of as little as a few generations. Bear generation time is what, 5 years? They coexisted with humans for a long time now.

Now, traits with weaker genetic components (i.e. if bear aggression is only 50% genetic) can take much longer. Even more so for traits with low variance, or highly complex traits and behaviors. But evolution isn't always slow. Certain changes can happen quickly - about as quickly as you can apply the selection pressure.

Evolution works in bursts. Species can stay stable for millions of years and then evolve in relative blink of an eye when the environment changes.

Right, how do you know the gene pool now mostly contains large aggressive bears that instinctively stay away from villages, and small cuddly bears that are enjoying left over pasta suppers ?

Maybe it's just that many of the large aggressive bears living near villages have just been shot or scared away, but the genetics is unchanged and the offspring of large aggressive bears currently living away from villages will have no aversion to trying their luck in the village ?

Oh right, the animal.

Looking forward to bears being domesticated.

that'd be a nice monthly food bill, a black bear can eat 20x as much as a dog

well breed it smaller then

I’d take it on if I could have a dog level trust bear.

“Widdle Yogi would never hurt nobody! Go ahead, pet hi… BAD YOGI! DROP IT NOW!”

"He's friendly!"

We can try to breed little chihuahua or pug sized bears that will curl up at your feet.

Suddenly I’m very pro genetic modification as long as we get mini pet bears. Dang it!

Surprisingly, chihuahua bears are not my idea of a good time.

I feel like something bigger would actually be better, like somewhere between a collie and a GSD. Labrador-size and temperament bears would be about the right speed, maybe.

Hah, where does the new breed land on the temperament wheel... Is it going to be more like a koala, raccoon, weasel, badger, or tasmanian devil?

How does that compare to a horse? I want a saddle-broken bear.

But it can catch salmon!

The coon's too: https://www.scientificamerican.com/article/raccoons-are-show...

Some Russians have been trying: https://www.youtube.com/watch?v=IM0GEN_CNfI

When will humans evolve to be less aggressive before we devolve into catastrophic collapse?

For what it’s worth, I think even the worst outcomes wouldn’t necessarily force us to extinction. Would be a bit of a reset though.

We already did. Most of us, anyway. Unfortunately it only takes a few percent to spoil it for all the rest.

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