What gorilla's upright walk could tell us about evolution
Louis is not like his fellow playmates. The gorilla has been a star at the Philadelphia Zoo for the past 14 years, but new videos have brought him nationwide attention. Weighing in at a hefty 470 pounds and standing at nearly six feet tall, the 18-year-old gorilla prefers to stand on two legs rather than on all fours. Don Dahler reports.