Bowhead whales are the only species of large whales

Last updated: 7/8/2022

Bowhead whales are the only species of large whales that live their entire life in the icy water of the Arctic Ocean. They have a couple adaptations that help them do this. First, bowhead whales have a thick layer of fat under their skin called blubber that helps keep them warm. The blubber of bowhead whales is 18 inches thick, which is thicker than any other whale. Second, bowhead whales have a remarkably thick skull. This allows them to break thick ice in order to get air to breathe. No other whales have such thick skulls. Available evidence shows that bowhead whales evolved from ancestors that lived in the warm waters of the Pacific Ocean and did not have either thick blubber or thick skulls. Which of the following is the best description of the role cold water played in the evolution of thick blubber? a. It forced all the whales to change so they could survive and reproduce. b. It made the whales work to stay warm and these efforts caused whales to change. c. It caused mutations that gave whales thicker and thicker blubber. d. It helped determine which whales each generation survived and which did not. e. It directly influenced the growth and development of the whales.