On our own two feet

Title- "On our own two feet"
Author- Stephen Whitt

Summary-
Walking on two feet without falling straight down onto our faces is a big challenge for living animals. In the article "On Out Own Two Feet" by  Stephen Whitt it says that the way we walk is "unique amongst primates but rare among all living animals". Years back scientists though that our brains developed before we started walking upright. They thought that our brains got bigger and that is the reason that we started walking upright. But they were wrong. Walking on two feet came a lot sooner before our brains started developing and getting bigger. Some scientists thought that chimps are our ancestors but to tell the truth they aren't. It is true that we shared the same ancestor years back but chimps are not our ancestors. Then scientists wanted to get some proof that chimps and we aren't related in any way. They took a chimps skull and a human skull. They compared them and this is the results they collected; our face (the human face) is relatively flat, while the chimps sticks out. Our brain case is much larger then a chimps, "its this rounded vault that really makes the human skull distinct", is what Stephen Whitt mentions in the article. Since we walk on our feet our skull can balance the upper body, which is our neck so we don't need very strong neck muscles. Another difference between the two skulls is that the foreman magnum on a chimps skull is " angled backwards and downwards to allow the spinal cord into the skull" as for the human foreman magnum it is horizontal because we walked on two feet. Then scientists added a skull of an A. afarensis to the examination. When they took a close look they came to the following conclusion;  the skull of A. afarensis  you would see that the face sticks out like a chimps but the foreman magnum is horizontal just like ours which means that it is almost like a combination of chimps and us. Another fact that we know about the A afarensis is that it walked upright just like us. Now another huge question appeared. Why did our ancestors stand up? Why did they walk on two feet? Here is a theory that scientists think is the most resealable. Scientists think that our ancestors stood up because they needed to carry food to their mates but the big WHY question is still being answered so for right know we only have theories.

Whitt, Stephen. "On Our Own Two Feet." On Our Own Two Feet: 26,27,28. Print.