According to the Biologists, the core crux of their findings indicates that Koalas have remained same throughout the historical years. Now their history is not new, they are living on earth for more than 30 million years. Evidence suggests that Koalas today are the same Koalas in the exact way when they used to thrive on earth about 30 million years ago. Therefore, they have gone through little or no variation, which is highly unusual because this is not true for many other animals (e.g., lions, tigers, Kangaroos etc.) and also the human beings too.
The scientists collected several evidences from the fossil vessels and analyzed their findings accordingly. From the evidences they received, they specifically concluded that all the ancestors of the Koalas which were about 30 to 40 million years ago, were hardly different from their present brothers that are living across the continent of Australia. However, more researches have been carried out to find any difference. But one thing is for sure that the scientists specifically identified about 18 different species of Koalas out of which on 2 are living on the Australian continent.
It is also specifically concluded that Koalas from millions of years have been well adapted to the local environmental ecology of Australia. Even though there have been consistent droughts within the continent yet still Koalas knew really well to survive, and whenever, the green plantation grew as of last 20 to 30 years, the Koalas population grew further as well. So from the historical perspective Koalas were physically very fit and complete species even before 30 million years ago and they still possess same quality without any physical evolution.