I can't get over the length of the arms of the babies at the zoo. Baby gorillas are going to grow up to walk most of the time on all fours, and this is possible because of those long arms. Some would say that gorillas have long arms because they walk on all four limbs, but no. It's more likely that they find it comfortable to walk on all fours because their arms happen to be long, and their hands happen to be big. And what an animal is comfortable doing due to his body shape, an animal will do.
As we have pointed out before in these pages, gorillas can walk on two legs for short distances. Songs of the Gorilla Nation describes a rainy day on which some of the gorillas at the Seattle zoo avoided the mud to the greatest extent possible by walking on two legs instead of squishing all their four limbs through the mud. This way they had less mud to clean off. Their feet got dirty but their hands stayed clean. Just another indication of the intelligence of the amazing species we call Gorilla Gorilla Gorilla.