How did bears turn to polar bears?

Answer 1

All animals change when they infiltrate new habitat to adapt to life in that location. It is believed, based on fossil record and DNA, that the brown bear, Ursus arctos, became isolated during a period of glaciation in the Pleistocene period and the animals who adapted to that colder harsh environment eventually became a new species, the polar bear, around 200,000 years ago.

Animals change/evolve to adapt and survive as habitats and food sources change. They can change over time into an entirely new species that is stronger and better suited to the current conditions because of the adaptations. The ones that manage to do well live to produce more offspring with the newest adaptations. While those who do not change or have changes that do not provide improvement for survival in the new habitat die. The offspring with each adaptation are a bit better able to thrive in that environment and more and more of the new offspring have the evolved characteristics that have been successful. These things continue on and on over hundreds of thousands of years through the genetic process of mutation and evolution.
it is called a polar bear because it lives at the north pole. polar bears only live in the Arctic (the north Pole) do not live in Antarctica (the south).