Loose of body hair, reduction of body fat percentage and changes in life habits.
Explanation:
One of the most notorious changes would be the loss of body hair, due to the temperature increase. The amount of hair that polar bears now posses, helps them with keeping their body warm in very cold temperatures, as well as the body fat, which would also be reduced because of the excess of heat. Finally, their life habits could also change, as for example, part of the body fat helps them with hibernation, so these periods could be reduced or even lost.
Based on the scenario being described within the question it can be said that the form of regulation that is being described is known as attenuation. In the context of genetics, this is a specific mechanism that provides control in various bacterial operons that result in term results in premature termination of the transcription.
