The flying squirrel of North America closely resembles the flying phalanger of Australia. They are similar in size and have long, bushy tails and skin folds that allows them to glide though the air. The squirrel is a placental mammal, while the phalanger is a marsupial. These close resamblances, even though genetically and geographically separarted by great distances, can best be explained by

This can be explained by convergent evolution.

Explanation:

The similarities between the two animals presented in the question above can be explained by means of convergent evolution. This type of evolution refers to living beings that have characteristics in common, even though they do not have the same point of origin, that is, even though they do not have a common ancestor. In this case, the similarities between these beings are not based on genetic inheritance, but were established through the influence of the environment in these two beings, which ended up changing in similar ways. Convergent evolution is created through natrual selection and environmental pressure on individuals, regardless of their genetic makeup.

explanation:

the universal gravitation equation. since the gravitational force is directly proportional to the mass of both interacting objects, more massive objects will attract each other with a greater gravitational force. if the mass of one of the objects is doubled, then the force of gravity between them is doubled.