The existence of parallel worlds, of course, raises a lot of questions, notably that of evolution. Did life evolve in exactly the same manner everywhere? Or is it all the results of migrations between worlds? I'm currently leaning towards a mix of both.
Isabelle is a young French woman who was brought through a magical portal to Sérannie, hit with translation magic, and told to help the Séranniens beat their Dark Lord. Only, once the questing party triumphed, she was forced back to the normal world. She is rather bitter about that.
While looking for a way to go back, she writes journal entries about her time in Sérannie to not forget what happened and to prepare for her return.
A different evolution?
The most striking thing in going into a different world and meeting a completely foreign culture is how, in fact, everything is not truly that different. Why are there even humans that look exactly like us? From that, I was expecting animals and plant to be the same too. And while I have no idea about the plants, as it's possible some similar species exist in the normal world on the opposite side of France, I can judge animals with certitude: they are different, but with just enough similarities to make it extremely creepy.
I have already mentioned horses and donkeys (here and here). Their donkeys are smaller to those in the normal world—about 1.2 m—and not rideable, but otherwise appear to be identical. Horses are also smaller and more stocky, with a large and thick head, and they do not seem to have been built for speed and racing as much as ours. They also cannot feed from normal Sérannian pasture or grains without them being supplemented with nutrients with the help of magic, making them very expensive to keep.
Horse by AmélieIS
Donkey by AmélieIS
Their cattle looks a lot like the prehistoric animals in the normal world—aurochs? They have massive, elongated, and broad horns that seem to reach about 1m in length and 20 cm in diameter. They are bigger than cows thanks to their long, slender legs. I'd estimate them at about 1.8 m for male and 1.6 m for female. They also have a big sexual dimorphism in colour, with male being black and female brown. They are kept by Séranniens for their meat.
Auroch by AmélieIS
Sérannie also has something that is either a goat or a sheep. Looking up at the ancestors of those from the normal world, ibex and mouflon, there is definitely a resemblance with their extremely long and curved horns that reach something like 1.5 m. They don't seem to have a big sexual dimorphism, with all animals having a dark brown and white coat that shift to grey in winter. The coats are sheared by Séranniens during summer. The animals are otherwise kept for their meat.
Goat by AmélieIS
Another important source of meat is a kind of boar that looks more like the wild boars of the normal world than pigs. They still have some brown fur on themselves, and some small little horn.
Rabbits are about the same as in the normal world. They're kept in garennes and are used for their meat.
Similarly, a few birds almost identical to their normal world counterparts are also kept for their meats and eggs. I haven't seen any chicken, but they have ducks and geese, and some other types I could not identify.
Fish are kept in ponds in big farms and are caught in lakes, river, and the sea. However, I do not know enough about what the fish in the normal world look like before they get onto our plates to be able to compare them with Sérannian fish.
Wild boar by AmélieIS
Rabbit and birds by AmélieIS
Séranniens don't keep a lot of animals inside their houses, especially if they live in the tiny apartments of the cities. When they do, those animals are not pet per-say but worker in their own right who have to do their jobs to earn their keep.
The most common interior animals are cats and dogs. Cats look exactly the same as in the normal world. They have varieties with short hair and some with long, and I think they have a similar range of colours. Cats are very necessary to hunt all rodents and other vermin, as both the countryside and the cities are full of them. Sérannian cats also appear to have a high sensitivity to magic, and, as ambush predator, they're great at guarding houses and attacking and maiming any intruders.
Fierce kitten by AmélieIS
Thus, dogs are not the animals used as guards in Sérannie. They also look very different from those in the normal world. They seem to be closer to their wolf ancestors, being just as big, but very thin—emaciated, almost. They are kept as hunting animals because of their highly developed sense of smell, and they look ferocious. Some of them are even trained for military use as "hell hounds", both by the royal army and the Dark Lord. I know from our time on the Quest that getting chased by those monstrosities is not an agreeable experience.
Dog by AmélieIS
Impact on society
Like I've written before, as a result of all of this, travel and transportation by horse is near unheard of. The only exceptions would, of course, be the royal family and top senators and generals, but even then the horses would only be for themselves and not their entourage. Everyone else has to use small donkeys to drag carriages or for short travel to use palanquin. Or walk.
Similarly, all labour on farms is done with those donkeys. Magic can also be of some assistance, but most Séranniens do not have the education to make it do more than simple tricks. And artefacts allowing for anything more complicated are expensive. As such, donkeys are used in the crafthouses and warehouses of the cities in a way similar to the use of machines in the normal world.
The difference in evolution also has an impact on food, although I'm unsure how much can be attributed to it versus culture. Séranniens do not have any cheese and rarely use animal milk.
At least, they have lots of eggs.
Palanquin by AmélieIS
So I'm not sure what explanation to go with for Sérannie. Human could have travelled between worlds by accident sometimes in our prehistoric past, explaining why we are so similar rather than Séranniens being Neanderthals or something like that. And if that interworld portal stayed opened long enough, animals could have gone through too, then be nudged towards different evolutionary paths. After all, us humans influenced the evolution of domesticated animals a great deal since the invention of agriculture—and even before in some cases!
That would explain why plants are much more different, but animals can still be recognised as related to those from the normal world. Note: learn more about fish while I'm in the normal world, as they're unlikely to have been able to travel between worlds unless portals also opened in the sea!
Or, the way parallel worlds work means they're all duplicates of each other, with one singular evolution point in the past from which they diverged. But with the existence of magic and the way the continents are so different in the fantasy world, it seems less likely. Unless magic can affect plate tectonic? Note: research about volcano and how explosions are different—by asking, not by going there!!!