The Evolution of Bipedalism; Who freed the arms?

When we are describing someone, we look at their eyes, hair, height, weight, and other physical features. Something we don't often look for in a grown adolescent is if they are bipedal, or if they walk on two feet. This is something that is expected in humans, and we sometimes take it for granted. We are the only domesticated animal that can walk on two feet for long periods of time. Modern humans, Hominids and other early humans with advanced features are literally built for walking. We have a wide blade at the hip bone, long legs, and a spinal cord that will support us walking on two feet. Archaeologists believe that humans started walking around 3million to 6million years ago, the question is, why did we start walking? Most animals were doing fine on all fours, it was efficient and it didn't require adaption. Scientists have a variety of theories one of which is that they needed hands to make stone tools. Some are more believable then others, but there are three that have the most concrete evidence to support them. Although we have many theories as to why people started walking, we may never know the real reason.

Changing environments
Africa was once covered with trees. Early hominids could shelter themselves, find food, and keep themselves safe from predators. Then the trees stated to receed, leaving the hominids and all the animals they hunted homeless. The other animals had to migrate to find new shelters and the hominids probably followed through the Savanna. Grass in the Savanna grows to be about five feet tall, and the bones discovered of hominids were about that size or shorter. It is hypothesized that early people stood up in order to cross the grass safely and efficiently. Walking on two feet is energy efficient, allowing the hominids to walk for greater distances, and it also allows them to see approaching predators with hindsight and react quickly.

More food
Another theory of the hominids is that we stood up to obtain more food. Hominids obviously had to hut their own food. Casing or picking prey on all fours would prove to be a challenge when you needed to pick fruit or hunt meat. By learning to stand up hominids could run and hunt faster, and pick fruit and other foods from higher branches.

More attractive
A third theory of why we stood is that it was more appealing to the opposite sex. Bipedalism allowed hominids to hunt easily. Like peacocks, males would try and impress the females. He would often show off by carrying food ,which showed that he could provide for the female and her family. Not only did walking on two feet allow hominids to provide for their families, it also allowed them to carry more. Having two free hands will obviously allow you to carry more, and the hominids must have figured this out.

Whatever the reason, the evolution of bipedalism changed the way we evolved to the advanced humans we are today