Bipedal Hominid Evolution

          There are many different theories that attempt to explain why early humans became bipedal.  No one knows for sure. Some think it was an adaptation, and others believe that we grew this ability after our brain developed, because we realized that it's easier to walk on two feet than on all fours.  There are endless possibilities.
          Some people believe that we evolved bipedalism in order to free our arms.  Back then, we needed to carry food and make tools, and when walking on four feet instead of two, it was much more difficult to carry food to a mate, or lug stone or wood to build crude dwellings.  With both hands free, you could transport the maximum amount of materials you could hold without worrying about dragging them in the dirt or dropping them.
          Others think that we grew into bipeds because of thinning African forests.  We originally lived in trees, but if the flora in one forest died out and we didn't have enough food or space, we would have to migrate over the tall grass of the African savannah.  The grass in Africa was/is at least 5 feet tall, and walking on all fours would have kept you too short to see over the long grass.  This restricted your ability to watch for predators or keep a straight path, and just know where you were headed.  You could get attacked by ancient predators, or you could just get lost - both big problems.
          Another theory that attempts to answer the mystery of why we are bipeds is the thought that standing on two feet was a better way to for male hominids to engage mates (female hominids).  We could dance, wave our arms, do little mating dances, and use our height to dominate over other males if we could stand up.  Maybe, once a female was pregnant, the male had to collect food for her and the kids, and it would be much easier for him to do that if he had the use of hands.
           One last reason that explains why humans can walk on two feet for an extended period of time is the theory that we had to reach up into trees to grab fruit.  Scientists believe that we were able to walk part-time in trees, and if we had to hold on to branches and tree limbs all the time, we wouldn't be able to grab nuts and fruits.  If we could stand up on tree limbs, we would be able to reach high branches with nice edible fruit. 
         Nobody knows for sure why we evolved bipedalism, but one thing is for certain - it has made all the difference in the lives of all the humans on the planet.