Whitt, Stephen. "On Our Own Two Feet." Odyssey Adventures in Science Oct. 2009: 26-28. Print.
ON OUR OWN TWO FEET
The article “On Our Own Two Feet” by S Whitt presents our “missing link” between humans and apes. The author also talks about the similarities and differences between humans and apes. The article discusses many interesting facts about ape and human skulls. Ape skulls have a jaw that is more jut out than ours. However, our skulls have a much larger brain case. An Australopithecus Afarensis, which is one of our early ancestors, has a jaw that juts out and a smaller brain case similar to apes even though they are one of human’s earliest ancestors. Another difference between ape and human skulls is the positioning of the foramen magnum. The foramen magnum is a hole at the bottom of the skull where the spinal chord fits to connect with the brain. The foramen magnum of an ape needs to be a bit backward and downward. It needs to be like this because apes walk on all fours so their spinal chord is positioned so that it angles up a bit. Our foramen magnum does not need to be angled a bit back and downward rather it needs to be horizontal because our spinal chord is vertical. As apes "walk on all fours, their spines angle up slightly, but are nowhere between up and down". If you look at the foramen magnum of an Australopithecus Afarensis you would notice that it is horizontal, like ours.
The author talked about bipedality as well. Scientists now have evidence that may be even older than Australopithecus Afarensis. Bipedality may have started with Ardipithecus Ramidus and even Orrorin Tugenesis. Both of these early hominins are older than Australopithecus Afarensis. A previous theory about the purpose of bipedality was that early humans needed bipedality to be able to make and use stone tools. But the fact that stone tools were created after hominins became bipedal prove the theory wrong. One other theory is that hominins became bipedal because they needed to carry food to their mates in their hand while walking. As the author states, “By sharing food we made it possible for one parent to focus on raising children.”
The author talked about bipedality as well. Scientists now have evidence that may be even older than Australopithecus Afarensis. Bipedality may have started with Ardipithecus Ramidus and even Orrorin Tugenesis. Both of these early hominins are older than Australopithecus Afarensis. A previous theory about the purpose of bipedality was that early humans needed bipedality to be able to make and use stone tools. But the fact that stone tools were created after hominins became bipedal prove the theory wrong. One other theory is that hominins became bipedal because they needed to carry food to their mates in their hand while walking. As the author states, “By sharing food we made it possible for one parent to focus on raising children.”
An Ape Skull in comparison to a human skull
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