The standard explanation among anthropologists has long been that early hominids left life in the trees to forage on the increasingly open savanna and that walking upright was key to surviving in the new environment. This biped gait led to a new means of travel, running. Homo erectus was most likely a long distance runner, either to escape predators or hunt prey to exhaustion. During this transition in our evolution our physical features changed quite a bit.
Most scientists reason that Lucy, the 3.2 million year old ape, with her chimp like build, could not have been a good distance runner. Her short legs, wide waist, long arms, and curvy fingers and toes, suggest a tree climbing lifestyle. More than a million years later Homo erectus roamed Africa with a much longer, leggier build and supporting many different attributes.
Development of abundant sweat glands and less fur allowed the body to keep cool over extended periods of exertion. Most animals pant to cool their body temperature, a cheetah for example, while extremely fast, will refuse to move once its' internal body temperature reaches 105 Fahrenheit. Our sweat glands and exposed skin allows us to control our body temperature while continuing exercise. We also developed an Achillies tendon. This tendon allows the body to absorb the impact of the body and spring us back into the air. To aid in the gait of running we developed a gluteus maximus and big knee joints, which gives the hip and knee joint the swinging motion. All of these attributes are specific to running, not walking. It is a very strong possibility that early humans ran up to 100 miles within 24 hours to hunt prey or avoid being killed.
Ingfei Chen
