Theoretical Evolutions of Domesticated Lions

Question

So in my fictional universe there is a collection of tribes which, over the millennia, domesticated a closely related ancestor to modern day lions, much like how humans domesticated closely related ancestors to modern day wolves, what kinds of evolutions can one suspect them, the lion-ancestors, to undergo? And let us assume, for simplicities sake, that they are for all intents and purposes identical to modern lions.

So far what I have is:

Becoming more sociable

Smaller Size

Increase in synaptic plasticity

What other changes can on suspect? While I did find much on the neurological changes in domestication, I cannot find much on physical changes outside of those brought about by selective breeding.

More Context:

For more context they were domesticated in much the same manner was wolves, they were assisted by humans, and assited humans in hunting of fauna and megafauna, over a long period of time, and soon began seeing them like members of the pride, and underwent the changes that come with domestication.

Answer 1

I think in order to understand how they would evolve, you'd need to clarify what purpose they fulfil within your fictional society.

Wolves are persistence predators, and one of the few predators in the world who can keep up with human persistence predation tactics and actually be useful for hunting things. This is one of the major reasons they have been domesticated where a dizzying array of other predators haven't.

Big cats are ambush predators, and as such tend to run out of puff very quickly (but be capable of immense speed and acceleration over a short distance). This is not as complimentary to human hunting characteristics as the lions can't keep up with humans, and humans blow the lions' cover (and are too slow to effectively ambush the same prey).

Cats were domesticated for entirely different reasons. They're a vermin-management service, eating mice, rats and small birds that would otherwise eat our stored grain. The process for this was less directed than with other domestication events as humans basically created environments that are great for small cats that eat mice and the cats moved in. I can't see how you'd start off with man-eating cats at this point, and breed them until they live off mice.

A possible solution

So, what you're looking for is a set of circumstances that would mean it's desirable for humans to work together with big cats, and importantly that it's desirable for big cats to hang around humans as well (rather than just eat them). Domestication (especially early domestication) is a two-way process. For wolves, proximity to humans (and ultimately participation in joint hunts) meant that they increased their success rate for getting food, and for cats it meant a steady supply of small vermin for them to eat concentrated in one area. You need a situation that's beneficial to both parties (and the more proximate that benefit the better).

You're going to have to invent some things to engineer this situation. Perhaps some sort of animal that needs the physical strength of lions to bring down, but perhaps has a level of armour plating that means it needs tool use to butcher (or maybe has poisons that need cooking to remove, but that is a longer shot as lions would have quickly learnt not to bother hunting those).

Or perhaps there are migratory animals that are susceptable to ambush-predation which gives lions a glut in part of the year, but for the rest of the time the game around is only really vulnerable to persistence predation. In the early days, humans scavenge off lion kills in the plentiful season (or drive them off them), and lions drive humans off their kills in the fallow season. Over time, this develops into humans leaving parts of their fallow-season kills on the periphery to keep the lions fed (and stop them driving them off their kills), and lions permitting humans to scavenge the bits of their plentiful-season kills they don't need.

The reason I put this option second is that the benefits are less proximate, which means it's harder for both parties to see the other as a benefit and not a competitor. It's also lacking a truly collaborative hunting aspect which would reinforce the thought that both animals are part of the same group. However, it's a bit of an easier option to extrapolate from so we'll use it for the next step.

So what might that mean?

In terms of evolution, I think you're right that they would reduce in size slightly and become more co-operative.

You might see them become faster and more greyhound or cheetah-like as that would make them better at ambush predation, and they wouldn't have the fallow-season enforcement of persistence predation checking their evolutionary change in that direction.

You could see breeds a bit like servals being bred for catching birds, or large guard-breeds that spend most of the time lazing around in one location but are powerfully built. Cats can also climb where dogs can't, so they might be breeds of use for hunting arboreal creatures (although, alongside the bird-catching variants, would need to be smaller and change their hunting behaviour so would probably be later developments).

Basically, in this circumstance (and any other circumstance), you need to trade the benefits of dogs (high endurance) for the benefits of cats (high acceleration) and see what uses humans could put that to.

Answer 2

Well, think about it like this, my dachshund looks absolutely nothing like a wolf, and yet, through a few generations of selective breeding later, here he is, a bonafide, wiener shaped, wolf descendant.

When individuals are looking to breed animals, they look for certain valuable traits in purebred stock for a certain purpose, or may intend to use some type of crossbreeding to produce a new type of stock with different, and, it is presumed, superior abilities in a given area of endeavor. For example, to breed chickens, a breeder typically intends to receive eggs, meat, and new, young birds for further reproduction. Thus, the breeder has to study different breeds and types of chickens and analyze what can be expected from a certain set of characteristics before he or she starts breeding them. Therefore, when purchasing initial breeding stock, the breeder seeks a group of birds that will most closely fit the purpose intended. https://en.wikipedia.org/wiki/Selective_breeding

So if you assume domestication, at even its most rudimentary level, has already taken place at the time of the narrative, you can assume that for any type of dog breed on Earth there could be a corresponding lion breed on your world. a good resource might be the American Kennel Club's guide to breeding dogs. You could take up the narrative from an almost bureaucratic stand point of new laws and licensing requirements pertaining to new breeds, or overbreeding. Can you imagine a landscape of roaming semi-domesticated, hungry and neglected, lions on the hunt might look like?

Have fun

Answer 3

They wouldn’t be much different from our current cats.

Cats (of all species) are not as anti-social as popularly believed; they are as social as their food supply permits. The issue is that big cats need an enormous amount of food, so aside from lions (which hunt enormous prey), one territory can rarely feed more than one cat. However, many species of cats big and small have been observed sharing territories and even sharing kills when prey is sufficiently abundant.

The wandering is the real problem with cats. The most significant difference between housecats and their nearest wild relatives is that the former have the “homing” instinct, which means they recognize a specific place as their home, whereas the latter are equally at home anywhere in their territory and will change their territory as needed to feed themselves (or avoid conflict). So, you need to either select for homing lions if they appear naturally by random mutation, or you need to somehow introduce it into your stock by cross-breeding. Unfortunately, while small cat species are remarkably inter-fertile, big cats are not, so you may be waiting a long time for the former.

Another issue, oddly, is that you need to select for dumb cats. Studies show that every domesticated species has a smaller brain and exhibits less intelligence than their nearest wild relatives. My guess is that less ability to feed themselves makes them more reliant on humans and thus more easily trained or at least handled.

All of that said, you might look at the many, many species of lesser cats, many of which can be almost as easily socialized as housecats without the hassles of selective breeding you’d need to shrink a great cat. The only thing that’s missing is the homing instinct, which you could transfer to them by limited interbreeding with domestic cats. In fact, you might do better starting with such cats and then trying to selectively breed them to be larger!

Answer 4

According to fox domestication, they would keep some of the young-age features

A well-known Russian experiment is about taming and domestication of foxes. per the Wikipedia page, these foxes tend to keep some young age features

The changes manifested by the tame foxes over the generations, moreover, were not only behavioral but also physiological, just as Belyayev had expected. The first physiological change detected in the tame foxes was a lower adrenaline level. Belyayev and his team "theorized that adrenaline might share a biochemical pathway with melanin, which controls pigment production in fur", a hypothesis that has since been confirmed by research.[6] After eight to ten generations, the tame foxes began to develop multi-colored coats, a trait found more in domesticated animals than in wild ones; this was followed by the development of "floppy ears and rolled tails similar to those in some breeds of dog". After 15 to 20 generations, a very small percentage of the tame foxes developed shorter tails and legs and underbites or overbites. The experimenters also discovered that the domesticated foxes show a "fear response" several weeks later than their wild counterparts, and that this delay is "linked to changes in plasma levels of corticosteroids, hormones concerned with an animal's adaptation to stress". After 12 generations of selective breeding, the corticosteroid level in the tame foxes' plasma was "slightly more than half the level in a control group". After 28 to 30 generations, "the level had halved again." At the same time, the tame foxes' brains contained higher levels of serotonin. Moreover, tame male foxes' skulls gradually became narrower, more like those of females, and litters became, "on average, one pup larger"

I think that domesticated lions would for instance have smaller manes (the males) and maybe would keep the slightly spotted skin of the puppies.
But it would not be so certain: the foxes of the experiment were bred mainly for their docility trait, but these lions could be bred for different traits.

I expect that, once fully domesticated (in a time span of about some hundreds year), the human breeders would start to select different traits, according to the utility, such as size, instinct to territoriality and so on.

Of course, the true problem is that lions are not as easy to feed than other animals. The only carnivore animals that were domesticated are the dog (but because wolves can adapt to eat everything) and the cat (who is an obligate carnivore, but doesn't need a lot of meat because of its size).
So in case of lions, I expect that the breeders would also try to select the smaller ones, in order to have animals easier to feed.

Answer 5

In a video about a Russian project on domesticating foxes, the foxes started to become greyer and their ears to become more soft and fallen to the ground, like the dog ones.

"We met the world’s first domesticated foxes": https://youtu.be/4dwjS_eI-lQ

The thing is that, just like us, the more the foxes started to look more sociable, the more they looked like infant version of their species.

Even though foxes and wolves aren't much like Lions and cats, you could also considerate these changes.

Not to mention the social structure of lions would be severely be changed and affect their relationship with humans and other pets. Like pissing in all their territory, eating a crap-ton of food, sleeping more than 14h a day, roaring all night like dogs barks all day, ruining sofas with their powerful nails and jaws and probably eating the neighbour's dogs.

BUT, if you really want to nail the way they act in a daily basis, you will need to study more about wolves/dogs and cats/lions behavior and social structures to make comparisons and build up your domesticated Lion.

Also, a bonus, there is a russian couple that is raising a cougar that was too small and weak to be released into nature and was rejected by its mother. It could also be used as a reference for your lion.

"Couple Share Studio Flat With A Cougar | BEAST BUDDIES" https://youtu.be/OkO7be9Dn2c

They also have a channel were they make daily uptades on their cougar and other wild animals they interact with:

https://www.youtube.com/channel/UCvph04Sh9CFKAw-gA6y-brQ

Also, another bonus curiosity: Cheetahs are too stressed, so the zoos give them companion dogs to help them keep calm. Depending on how your tiny-lions behave, you could also add a type of animal they are good to interact with, like cheetahs and dogs or crocodiles and those birds.