What evolutionary pressures would lead to Ogres?

Question

In a world I am writing, there is a species with a super-expansible stomach called ogre (their scientific name is Homo corpulentus) (Homo corpulentus means "corpulent human", so they are humans, just not Homo sapiens). They look a little bit like Shrek ogres (formerly, they were a cannibalistic race, but there was a revolution that made eating human meat unethical, they are as intelligent as humans, but they do have weird practices). Basic characteristics of my ogres include:

1. They are as solitary as orangutans.
2. They can drink saltwater without getting dehydrated.
3. Females are larger than males (great white shark-like sexual dimorphism).
4. Their average size at sexual maturity is 1.98 meters tall and 140 kilograms (or 6 feet 6 inches and 308 pounds), and they are adolescents/teenagers all their lives, in the sense that they never stop growing (like kangaroos, elephants, and crocodiles).
5. They have an average lifespan of 11 decades (110 years), and the world record for the highest life expectancy is 18 decades and a half (185 years old).
6. They have an improved sense of hearing and eyesight, but they do have a worse sense of smell.
7. They are erect bipedal.
8. They have a seal-like blubber.
9. They are omnivorous like brown rats.
10. They can interbreed with anatomically modern humans.
11. They have a lower risk for osteoporosis, senile dementia, and noninfectious heart disease, and a higher risk for type 2 diabetes and noninfectious cancer.
12. They are less fertile than anatomically modern humans (the twin birth rate for ogres is 3 to 7 twin sets per 1,000 births) (the twin birth rate for anatomically modern humans is 9 to 16 twin sets per 1,000 births).
13. They have gorilla-level strength.
14. They overwhelmingly have B blood type, and they have a bit more Rhesus negative blood than anatomically modern humans (I do not mean Rhesus null, but the simple absence of D antigen).

Answer 1

Two of these could be explained by the "aquatic ape" theory: seal-like blubber and being able to drink saltwater. A marine ancestry or amphibious lifestyle (also shore living) would explain how they can deal with the salt; they likely "cry" it out like marine iguanas or crocodiles.

Almost everything else (omnivorous, bipedal, similar size and lifespan) points to their being closely related to either Homo Sapiens or Neanderthals. It turns out that Neanderthals lived in small, isolated groups, so let's go with them. That should cover your 'solitary as orangutans' bit, as orangutans are highly socially tolerant despite their semi-solitary lifestyles.

As for hearing and eyesight, along with poor smell, humans (and most mammals) can't smell underwater, since we can't inhale without drowning ourselves. If your Ogres live on islands that are scarce in resources on land but not in the water, they could very well evolve into amphibious beings that can take advantage of the sea's bounty.

This amphibiousness and their island lifestyle would explain:

1. Their solitary natures-on top of being evolved from less social Neanderthals, they are naturally more isolated (and therefore more solitary) due to their island lifestyle and the large territories they'll need to sustain themselves

2. Omnivorousness-if you don't have much to eat, it makes sense that you'll evolve to eat whatever you can get

3. Their ability to drink saltwater-they live on islands, freshwater is hard to come by, they need to deal with salt anyway since they dive and swim in the sea so much....

4. Senses-Since smell is useless underwater, but sight isn't (don't forget hearing, which still works underwater), they should have evolved to reflect that. Ergo, they have a poor sense of smell but great vision and hearing. Additionally, they hear much, much better than us underwater.

5. Extra-expansible stomachs/blubber-If these Neanderthals evolved in a "feast or famine" type environment, which should be more than possible on a tropical island with dense forests, they would have adapted to eat as much as possible, storing fat and nutrients for the lean times to come.

As for large size, that's more feasible for shore dwellers. However, it's not impossible that these island dwellers defy the tendency to dwarfism because of intense competition for food and resources (perhaps from tribes of their own species) that makes bigger sizes more advantageous.

They can gain the energy required to sustain their large bodies by eating a lot of seafood-while the island may have limited resources, the sea doesn't, and if they can swim like polar bears, they have an awful lot of territory to feed off of.

Answer 2

Evolution can lead to any result - just not a planned one

The way evolution is an incremental change that gives an advantage at the time, so there is no 'great plan' for evolution.

So Giraffes don't suddenly have long necks to get to the tops of trees. What happens is a short necked Giraffe has a slight mutation that makes its neck slightly longer, which appeals to a mate and makes it sexier, which then allows it to have more children, who can then have the same chance at random mutation. Over many generations its neck can get longer to the length it is today.

At any point though, the Giraffe generations may have shorter necks, however there must be a sexual, or environmental, reason for those to not have as many children at the time.

So for your ogres, I would imagine you would have a starting point of a very similar creature, with the developments your outlining to be incrementally (ie: Very slowly) implemented through sexual or natural selection.

I would start with humans, as your traits are virtually human anyway, and start with:

• A strong cultural allure for large women, every man wants a large/tall woman, so have more kids with them. This is sexual selection, but must apply over many generations.
• There is an environmental catastrophe where water is very scarce, and salt water more prevalent. It is cruel, but all those that can't drink salt water slowly die out (although this is hard, the reason why salt water is not able to quench thirst is our kidneys need freshwater to extract it, somehow there must be a way for this impediment to be removed) This is natural selection.
• Stretched stomachs / blubber stomachs can be an adaptation to overeating, with both sexual and natural selection pressures.
• All other traits in your list are mainly cultural or environmental.

Answer 3

Disclaimer, I also use these ideas in my own stories but you are free to borrow them.

Ogres could be from a unique jungle or forest where the trees have plenty of food to maintain their large size. Their original habitat is in an area that has trees which can filter water as mangroves do because its biome is on a lowland area which the seawater floods up its river delta and into marshland and swamps that make the foundation for the biome.

They'd be herbivores since most large animals tend to be eg. rhinos and elephants with the exception of whales which are carnivores. But you could make them omnivores if you want them to be more hostile and perhaps historically in times of famine they had to eat animals to stay alive.

The ogre would be a feminist system where the females rule since hight plays a lot into the evolution of humans social status which is along with endurance a lot of the reason males have dominated leadership and laws throughout history. In ogre coitus, the females would be on top.

Since in your story the ogres can drink seawater they'd have to have an extra hole with a semi-permeable membrane on their face so they can perform osmosis. On the outside of their body like where fish have their gills. Not on the inside of their stomach since that would just give them a leaky gut.
Since they have large expandable stomachs they would have a very slow digestive system to ferment and break down their food. Which would consist of raw flora and meats. They would not cook their food since that would mean the food would already be partly broken down and you may get lean Ogres. If the ogres can refine their food like in bread or something they would end up metabolizing it to fast and you would get diabetic ogres. Or who knows that could be a plot point.

Since they have a lot of blubber this would be to last hibernating in winter, travelling through snowy mountains to reach another prosperous oasis they can have their young. Or even for surviving long periods of time floating on their backs in the ocean before they reach new islands, they can colonize. This would also make sense since their solitary and after the offspring are born the farther could quickly yeet out of there and leave, leaving the mother to bring up the young vice versa. Then after they have leant the ogre how to survive and traditions the young would leave on their own journey for adventure and love in a distant land.

Bipedal depends on if they have to use their hands often for climbing or lifting or digging or if they've been taken up with wings in the case of a bird.

Since they live so long they'd end up breeding very late into their life and very rarely since that would increase the evolutionary pressure for evolution to program them in a better way to increase their immune systems and have a lower risk of cancer, cellular senescence removal of tau and amyloid-beta proteins in the brain as well as increasing the longevity of their telomeres and repair of double-strand DNA breaks increased epigenetic stability and maintain their glycans for longer.

They would be able to see colours as we do so they can find the right plants to eat. Since they are solitary nomads they could have a long-distance row to let other ogres know where they are and if their a potential mate or if their in conflict with a stronger predator.
Their sense of smell could be reduced due to them living in very foul-smelling swamps with a lot of rotting organic matter or other intense smells.

If they're not from the same genus as humans and are thousands of years apart and you want ogres to be able to cross-breed they'd need to have a close enough genome and epigenome. As well as their immune system would need to be excepting of the other species seed or they would have to be immunocompromised maybe by having their immune system knocked by some kind of antibiotic so they can perform successful coitus. I don't know much about reproduction so I may go a bit owo, but the ogre's sperm could have evolved some kind of adaptive capabilities similar to antibodies in its way of connecting their glycocalyx's glycans to the eggs I don't see why that last part would evolutionarily happen unless the female ogres mutated some kind of counterintuitive antibodies that try to attack the sperm and build resistance before it reaches the egg.

I wanna also talk about other fantasy species which seem like they'd be from the same evolutionary genus.
If orcs evolved naturally not being some tormented elf or something they would have more or less the same evolutionary path humans did starting off being hunted by other predators but then evolved a larger brain to outsmart them, so eventually they'd build tools so they could fight and eating them which would also serve as a catalyst for their more primal and violent nature. Orcs probably wouldn't be able to see many colours since humans evolved that for seeing fruit and vegetables. Goblins could have developed around a place where food was scarce so they evolve to be smaller, breed large litters when the season is right and be less intelligent and have shorter lives since they would have had no evolutionary pressure for longer life spans and instead opt for a more disposable soma.

Answer 4

A Predator:

• A predator would likely be solitary, large, and strong.
• Larger animals also tend to have less offspring on average (elephants, whales, etc).
• It would also contribute to being more perceptive for hunting.

Scarce pickings:

• They would have to store fat to survive in times of prey shortage.
• They would be able to eat both plants and meat. (Like bears)

Swamp/Marshlands:

• The difficult marshy terrain would make two legs and free arms beneficial, especially for a predator to out speed prey.
• Living near salt water would force resistance to salt water. (Sea Lions, seals etc)
• Strong smells in marshes would make other senses more useful.
• Shrek reference

The others, like sexual dimorphism, can happen in any species regardless of environment.

TLDR: A mammal predator in a scarce salty marsh.