What is the importance of the Arctic Circle in the nonfiction book, Your Inner Fish?

Neil Shubin focused a great deal of his focus on expeditions to the Arctic Circle. When he learned that the bones and fossils found in that region were much older than fossils he had been working with in Pennsylvania and the east coast of Nova Scotia, he made immediate plans to make an expedition there. His intuition paid off. It was there in the Arctic Circle that he and his colleagues discovered the creature that had elements of both fish and amphibian. It was later named the Tiktaalik and it proved the theory that many paleontologists and anatomists had held for years that there was truly a missing link – a creature that had features of fish as well as features of amphibians.