| MadSci Network: Zoology |
To become a koala took some time. Its ancestor responded to environmental conditions and evolved the best it could with its representative gene pool/ mutations to fill that particular niche (meaning basically the animal's job within the environment). That is how evolution works. The koala's niche is to eat a lot of eucalptus leaves, sleep 80% of the day, mate and to be cranky towards other males if you are a male.
A koala is a marsupial which means they have shorter gestation times and usually a pouch to carry their young. Some people theorize that the unique conditions (hot, dry, food & and good music) give marsupials an inherent advantage over placental animals (dogs, cats, you and me). This is just a theory but there are very few placental animals in australia besides introduced species. Australia is the land of marsupials and monotremes (echidna and platypus).
So the conditions of Australia created the koala and have also limited its migration. Hard to swim when you are a koala and find what you like to eat elsewhere.
Patrick
Try the links in the MadSci Library for more information on Zoology.