Evolutionary pressures for carnivorous elves

Question

In a fantasy world I am creating, there exists a race of elf-like hominids that exist along side other races in this world.

Note the "elf-like" portion as while they do have:

• Pointy ears (which move like a cat)

• More prone to injury

• Better eye sight

• Better sense of smell

• Slighter build

• Faster and more agile

• Slightly worse endurance

• Around 152.4 cm (5ft) to 155.448 cm (5'1ft)

These elves also have:

• Digitigrade legs

• Claws on the hands and feet

• Strong grip

• Run and walk in both a bipedal and quadrupedal stance

• Mane like hair that extends down the neck and lower back (other wise naked like us)

• Sharp teeth to accommodate purely carnivorous diet.

As you can imagine, these guys aren't exactly your typical elf. And you especially do not want live near the ones that have no qualms with hunting down other races for food.

My question is what evolutionary pressures could lead to a hominid to evolve these characteristics?

Note: Elves are descended from hominids.

Answer 1

Lack of vegetable/fruit matter foods for long enough would do the trick when it comes to making them more carnivorous, probably due to desertification or something along that line making their native habitat worse to live in for herbivores or omnivores. They'll likely be scavengers for a while before moving on to more aggressive predatory behaviour and actively hunting things.

The sandy kind of desertification will not lend itself well to the development of digitigrade legs, so instead of it turning sandy let's have everything turn into a rocky/craggy wasteland from an environment that used to be mountainous and forested but are now simply mountainous and rocky with little to no plants. You'll need the hard surfaces for the digitigrade legs to provide any significant advantage over not having them.

Claws and sharp teeth will be gotten from the natural tendency for carnivores to develop natural weaponry, while the eyesight and smell and hearing and ear adaptations will also follow suite due to them needing to be better at tracking and spotting prey and scavengible corpses. The more prone to injury part is typical of carnivores, I doubt carnivores walk away from attacks without at least a scratch or bruise somewhere, only on these things they'd be more noticeable due to the no fur part. Them becoming faster and more agile will also be typical of predatory adaptations, but why you'd want them to have less endurance(stamina?) is beyond me. Perhaps you want them to be REALLY fast like a cheetah but those speeds naturally come with overheating drawbacks.

Strong grips come naturally from primate hands, and because they've probably already adapted strong grips for tree climbing beforehand, but these will be further enhanced due to the rocky mountainous areas requiring a lot of climbing and jumping around(where the digitigrade legs will come into use quite nicely). For their running and walking to be functionally capable of both bipedal and quadrupedal locomotion I'll recommend that the length of their arms increase to make it less awkward with their behinds in the air due to the longer legs(it'll also help with climbing to cliffs and attacking).

The mane-like hair is typical of mountain-dwelling primates, no need to engineer specific circumstances for it to come about, though why they still remain naked for the rest of the body you may have to hand wave as it'll get rather cold in this region at night. Might require many caves for shelter from the winds or penguin group warmth behaviour(assuming they don't develop clothes).

Answer 2

Your elves look a lot like bears, with the only difference that they are not plantigrade (which explains also their agility and endurance).

I therefore guess that similar evolutionary pressures and circumstances which lead to the evolution of bears could, if applied to an early ancestor from the hominid branch, lead to the development of your elves. In particular they should get a strong advantage by being totally carnivore, while the bears are omnivorous.

Answer 3

Pure carnivory is uncommon, and its rapid evolution needs a special reason

Six percent of a wolf's diet is plant matter and berries. Here's a cute video of a crocodile eating a pumpkin. Here's a (self-described) review of the top seven vegan dog foods. Also, at least thinking of land mammals, to be a "carnivore" means to tear indiscriminately at the something's innards, and to develop some tolerance for the deteriorating remains of a past kill. As a result, carnivores tend to moonlight as scavengers, and can consume the scats of other animals.

For something to evolve pure carnivory, it means there would have to be some fitness cost to even sampling vegetation, so that even the thought of consuming non-flesh would evolve to become revolting, perhaps through a reworking of the innervation by olfactory neurons expressing particular odorant receptors. This means that the plants are not merely inedible - they are actively toxic to your 'elves' in a way they couldn't evolve to deal with. Or perhaps there is some pathogen that cycles between the elves and plants the way pork tapeworm cycles from pigs to snails.

Becoming facultative bipeds, parabolic ears, clawed hands, strong grip ... these tell a story, where a prey animal (perhaps a small primate) can be heard venturing down into the low branches of a tree, and they stealthily sprint and stand to drag it down and kill it right away. If it moves they can run on two legs to follow. They may be able to follow by climbing into the tree, but their quarry is apparently rather agile also, and this can't be a substantial aspect of their behavior or they would have better fur or tougher hide to deal with a charge into branches.

They likely live in areas with a large number of such trees, and explore large regions before waiting in ambush, accounting for their keen sight and smell and "slightly worse endurance". (Some humans, certainly not me, are the world champions of endurance, and can capture or otherwise make use of horses simply by running after them until the horse wears out: "persistance hunting". So the species you describe still has exceptional endurance by carnivore standards.)

Answer 4

Savannah Elves

The elves are descended from an arboreal omnivorous species of forest-dwelling elf-monkeys.

Being omnivorous the monkeys could eat fruits and seeds but not leaves, twigs or grass. They also ate small mammals, eggs, insects and such.

Their sharp teeth were good for eating meat and sufficient for eating everything else. They did not for example need specialized grinding surfaces since they didn't eat grass or leaves.

Claws and digitigrade legs explain each other. Since they did not grip with their back feet like normal monkeys, they need claws for climbing.

Their slim builds and agility were good for getting into the high treetops. Their strong grip was good for climbing.

Either the climate changed to make the forest a Savannah, or they simply spread outside the forest. Either way the Savannah has loads of grass which the elf-monkeys cannot eat. But it also has lots of grazing animals the elf-monkeys can eat.

Thus they eventually specialized towards a carnivorous diet.

Answer 5

Humans tend to eliminate, or at least marginalise, predators in territory they control as a matter of calorie competition removal. This leaves a number of potential carnivore niches that aren't filled in our modern world because we maintain pressure to keep them closed. However if the dominant hominids were as evolutionarily advanced, and shared our aversion for competition, but were universally severely night blind they would still put the same pressure on purely instinctual carnivores through hunting and setting traps for predators on their lands during the day. They would then leave a niche open for a nocturnal hunter that was as smart as they were, able to go undetected during the day and slip through the defenses at night. Nocturnalism itself would create pressure on hominids to go carnivore if we assume a relatively human sensory suite too. We have very poor colour vision in the dark which makes determining vegetation characteristics like ripeness difficult to impossible, and telling potentially poisonous fungi apart equally challenging, meat becomes the safer food option.

Answer 6

Your elf-like hominids sound very feline: pointy ears, less robust (more prone to injury, slighter build), sharp eyesight and sense of smell, faster and more agile with less endurance, digitigrade with claws, carnivorous with sharp teeth. This could suggest that historically, they were be quick ambush pouncers like cats rather than endurance chasers like wolves or humans.

The strong grip and optional bipedal stance could be the result of evolving to make and use tools and hand weapons. A mane could evolve as a flamboyance for attracting a mate and/or to protect the vulnerable neck when fighting (for a mate or when taking down a prey animal).

So why both claws and a strong grip? Do they have a long childhood before reaching an age of intelligence during which time they have to fend for themselves? And develop greater grip as they reach an age of greater complexity? The grip itself could be used as a sign of maturity.