A fundamental constant is one that has to be measured by experiment, rather than being derived from any other quantities. Which values we choose to make fundamental and which ones are derived are somewhat arbitrary.
Koalas are native to southeastern and eastern Australia, living in forests of eucalyptus trees. They are basically sedentary animals that need to sleep a lot to give them time to digest their food. Being on the ground all the time would be a disadvantage, because predators could catch them easily.
The origin of koalas is still in ambiguity however, some of the koala fossils have been discovered in northern Australia dating back to 20 million years ago. In those times, northern Australia had been covered with a dense rainforest.