Earth

Entirely populated by only a single sentient species, Earth has made remarkable progress with their technology, making leaps and bounds every decade. Earth has been behind compared to the average planet in genetics, general medicine, nature, and agricultural science. They've been very ahead compared to other planets in military, political sciences, and mildly so in economics.

Earth's substantial growth eventually brought them back to the medieval era after a devastating plague, caused by overpopulation. This apocalypse had been foreseen in advance but all efforts to avoid it had been futile. The plague wiped out 90% of the population. The 10% that remained moved out of the larger cities. Without man-made pollution, the Earth's climate has cooled. Winter lasts longer and summer isn't so hot.

The other animals of Earth have been able to replenish their numbers. Predatory animals have become bolder, no longer fearing Humans. They have evolved to varying degrees, though none enough to be considered sentient. Even so, Humans avoid them as much as possible. Some have been referred to by their scientific name, rather than their common name.