Final answer:
The least advantageous adaptation for a polar bear in a cold, icy ecosystem is dark coloration, as it would make them stand out and be easily spotted by predators.
Step-by-step explanation:
The least advantageous adaptation for a polar bear living in a cold, icy ecosystem would be dark coloration to help it stand out in its surroundings. In such an environment, a dark-colored polar bear would be easily spotted by predators and have a harder time hunting for prey. On the other hand, polar bears have evolved long, sharp claws to help them dig through ice, thick layers of fat to help them stay warm, and the ability to hibernate during the coldest parts of the year.
Learn more about Polar bear adaptations