Could these trolls exist?

Question

In a world I’m designing, a group of Homo Habilis, Australopithecus Afarensis or even Paranthropus migrated into a northern Scotland environment becoming Trolls. These are not D&D trolls, but something else. I have a number of basic characteristics for these beings, and am wondering whether these characteristics are plausible.

The basics of my trolls

• Can range in height from 143.2cm (4ft 8in) to 228.6cm (7ft 6in) tall

• Are mostly covered in a thick, coarse hair. Like that of wolverines

• Have an average have a life span of 150-170 years (barring major injuries)

• Can fully regrow missing limbs in approximately 1025-1095 days.

• They are not significantly prone to cancers

• Have large noses, as well as cow-like ears

• Their diet consists primarily of plant matter, though they scrounge a certain amount of protein from insects and carrion and will rarely scavenge dead animals

• Have very sensitive eyes and are nocturnal

• Are mostly solitary but do form groups during the colder months

• Have sloth like claws for digging up roots and peat

• Have gorilla-like strength

• Have very rudimentary tool use

The question

• How realist is this?

• Could an early hominid like Homo Habilis or Australopithecus Afarensis even live long enough to evolve into these trolls?

• Are there any other traits my trolls would need?

• and what evolutionary pressures might lead to them

Edit:

I guess I should have been more clear with

Are there any other traits my trolls would need?

what i meant to say was are there any other traits that my trolls would need to survive in northern Scotland?

Answer 1

I think most of the traits you want are plausible for a hominid species, either due to a presence in closely related species or because we can associate them with a (stem cell based?) ability for continuous re-growth.
Given that some of the traits you envision, make them more comparable to great apes than hominids, I think something like that (or maybe a common ancestor) might be a better origin species for natural evolution than hominids.

As for comments on specific points:

Can range in height from 143.2cm (4ft 8in) to 228.6cm (7ft 6in) tall

This range seems a bit much to me if we assume that it all applies to fully grown adults (body plans need to be very tightly controlled, so size variation is usually not very big). It would probably make more sense that your trolls never stop growing, even after they exit the growth spurt of juveniles. Such continuous growth could be caused by increased basal levels of developmental programs / stem cells (which can also explain some other traits you want).

Are mostly covered in a thick, coarse hair. Like that of wolverines

I imagine this similar to a gorilla / great-ape, so most the genes are probably already/still there.

Have an average have a life span of 150-170 years (barring major injuries)

A bit higher than other mammals of that size, but given that the trolls seem to have increased health/regeneration this seems fine.

Can fully regrow missing limbs in approximately 1025-1095 days.

This is a tricky bit, because mammals usually don't regenerate tissue. However, it's definitely possible and - like the continuous growth - could be explained by a basal level of developmental/growth programs, which would also explain why it takes so long (even if those programs get more prominent when a full limb needs to be re-grown).

They are not significantly prone to major disease

Like the other answer already mentioned this is not very well defined - diseases come in terms of pathogens but also issues of the own body. For the latter limb/organ/... regeneration abilities would help a lot (i.e. the heart could over time recover from a stroke), while the immune system is of course needed against everything else.

Have large noses, as well as cow-like ears

Noses should be fine, the ears are more tricky (the other answer also mentioned that), as most hominids or even apes/monkeys have quite human like ears.

Their diet consists primarily of plant matter, though they scrounge a certain amount of protein from insects and carrion and will rarely scavenge dead animals

This seems similar to the diet of great apes, so it should be sufficient for an hominid of that size. However, northern Scotland will not provide nearly as much food as a jungle. It may be an explanation for their solitude life style though - they need big areas to find enough food.

Have very sensitive eyes and are nocturnal

One often comes with the other and shifts to or from nocturnal life styles have happened quite a few times during evolution.

Are mostly solitary but do form groups during the colder months

Most hominids (but also monkeys or apes) are quite social, so this is a bit untypical - it could however be explained by other factors such as food availability in scotland (see above).

Have sloth like claws for digging up roots and peat

Most hominids/monkey/apes don't really have claws so this is, again, untypical. Elongated nails are fine, but real claws seem a bit much to me.

Have gorilla-like strength

Have very rudimentary tool use

Both of these are fine and in line with the species origin / similarity.

Answer 2

Can fully regrow missing limbs in approximately 1025-1095 days.

The regeneration of lost limbs seems slightly suspect, if only because there aren't a whole lot of other complex animals which exhibit such features. Newts and axolotl show that it can be done by tetrapods, at least. Quite why such a complex and useful feature woudl have arisen in your trolls in the absense of some kind of evolutionary pressure is anyone's guess (by which I mean, yours to handwave). What hunted the trolls? What happened to it?

They are not significantly prone to major disease

...is a sentence absolutely chock full of weasel words, but I almost feel that this is less plausible than limb regeneration. "Disease" covers a vast range of very different pathologies, and for your trolls to be somehow immune to whole swathes of these seems pretty peculiar, given how different eg. genetic illness is from parasitic illness is from viral illness is from bacterial and so on and so on. They may be more prone to cancer than regular folk, given their regenerative powers. Things which improve cancer resistance are likely to interfere with the complex set of cellular changes and rapid growth associated with newt-like regeneration.

Have an average have a life span of 150-170 years (barring major injuries)

I think there's a tradeoff to be made between lifespan and regenerative powers, due to the risk of cancers. I'd almost expect your trolls to have a shorter lifespan than humans, for exactly that reason.

Handwaving in a high resistance to disease and cancer and regenerative powers would help explain long lifespans, but it is stretching the bounds of plausibility somewhat. If the long lifespan isn't critical to your setting, I'd be tempted to drop it.

Have large noses, as well as cow-like ears

Cows inherited their cow-like ears from their ungulate forebears. Why would a primate have them? You can just handwave it in, of course. I guess there's no reason not to. Just seems a bit odd, and unnecessary.

Their diet consists primarily of plant matter, though they scrounge a certain amount of protein from insects and carrion and will rarely scavenge dead animals

You should have a look at the sort of vegetation that grows in the north of Scotland, and think about the calorific demands of big brains and regenerating limbs. Growing seasons are short, and fruit species are limited in number. I would expect them to have bear-like diets... quite omnivorous, generally happy to eat carrion and sometimes even predatory. I'd expect them to eat shellfish, and probably fish too. Eggs would be another thing they would be good at finding, in the right season.

Have sloth like claws for digging up roots and peat

Have gorilla-like strength

Have very rudimentary tool use

Tools are for species who have brains but aren't well equipped for various food-acquisition tasks. Being really strong and possessing great big claws rather obviates the need for most primitive tools, because you've got the stuff you need to hand already. What would they even need tools for? Moreover, if you do have great big claws, your manual dexterity is going to be impaired somewhat, making you less able to use tools if you somehow felt the need to.

At the very least, I'd lose the claws. At least then there's a good reason to dig and poke with sticks and smash things with rocks, etc.

---

How realist is this?

Seems OK, I guess. There are a lot of complex traits that your trolls will have evolved all by themselves, and you have to wonder why they'd do that and where the evolutionary pressure would have come from.

Could an early hominid like Homo Habilis or Australopithecus Afarensis even live long enough to evolve into these trolls?

If you wanted them to, why not? The tricky bit will be handling their encounters with later hominins, and explaining why they survived the encounter when all the other members of homo did not.

Are there any other traits my trolls would need?

For what?

Answer 3

A big problem is that there is no evidence of primates of any type indiginous to Europe from 35 Million Years Ago and the colonization of southern Europe by H. Erectus H. Neanderthalis and those little trouble making H. Sapiens sometime between 270,00 and 215,000 years ago. Prior to that, all Hominids and close great ape species were largely confined to Africa and other nearby territories. Hominids didn't make it to Scotland until about 12, 800 years ago during an ice age.

Your two species were omnivors, but largely subsisted on fruit with some meat additions from time to time, mostly from carion and leftovers from carnivors and H. Habilis did not have the upper limb development that made it capable of the type of hunting that would make later members of the genus move to further north ranges (persistence hunting and ranged attacks) (upright stances at this time would be defensive only, allowing H. Habilis to see predators over tall grasses). Tool Use was not offensive at this time. Colder European climates would make their essential fruit and vegetation dietary components seasonal and they were not hunters capable of surviving in winter.

Again, keep in mind, Humans are the only primate that lived in Europe at all past 35 million years ago (the other primates were wiped out in an Impact Event in Siberia that lead to a minor mass extinction... you don't hear about it because of the two impact events that created a mass extinction the K/T Impact was, as many important scientists would no doubt note, a hella lot bigger and deadlier). Primates in Europe is a very recent nostalgia trend in terms of evolution and even then, humans aren't adapted to living in Europe yet (what... it's been almost 300,000 years: Can you grow your own fur coats and not steal it from other animals? No? Didn't think so.). Hell, your guys were from about 2.1 million years ago and they never got into Arabia.