NATURE's six-part series TRIUMPH OF LIFE presents the remarkable story of evolution and its survivors.

NATURE's six-part series TRIUMPH OF LIFE presents the remarkable story of evolution and its survivors.

NATURE's six-part series TRIUMPH OF LIFE presents the remarkable story of evolution and its survivors.

NATURE's six-part series TRIUMPH OF LIFE presents the remarkable story of evolution and its survivors.

Ironically, the powerful, dedicated canines profiled in Sled Dogs: An Alaskan Epic are little more than mutts. They are mixed-breed huskies that have endurance.

Ironically, the powerful, dedicated canines profiled in Sled Dogs: An Alaskan Epic are little more than mutts. They are mixed-breed huskies that have endurance.

Ironically, the powerful, dedicated canines profiled in Sled Dogs: An Alaskan Epic are little more than mutts. They are mixed-breed huskies that have endurance.

Ironically, the powerful, dedicated canines profiled in Sled Dogs: An Alaskan Epic are little more than mutts. They are mixed-breed huskies that have endurance.

Ironically, the powerful, dedicated canines profiled in Sled Dogs: An Alaskan Epic are little more than mutts. They are mixed-breed huskies that have endurance.

Dogs need more than just shelter. They need a nurturing home, food, health care, play time, and rewards for good behavior -- even a simple pat on the head.