Introduction
Walking Upright: Bipedalism
Bipedalism was a big part of evolution, it was the one that made us be able to use our hands, run, walk with two legs and other things. Walking upright not only brought us advantages throughout time it brought us new chances of survival.
By: Raquel Paladines
Human Leg Bones
- The biggest bone in our body is the femur that goes from the pelvis to the knee.
- Leg bones are large and strong to be able to support the weight of your whole body.
- The knee connects the legs in the upper part and the lower part of the leg.
Human Feet
- The shape our feet allows us to walk, run, climb, etc.
- Feet contains tendons, ligaments, and muscle that allow movement while bones make up the structure.
- The shape of our feet is like a hands shape but since it gets more weight than hands it is stronger but less mobile.
- The biggest bone is the calcaneus, this bone will have a slope and meet with tarsal bones who will point to the remaining bones.
- In the low part of the feet they have arches that are created by the angles of the bones.
Human Spine
- Accordig to an article of the Mayfield Clinic from our lateral side our spine has curves and with all the curves it looks like an S.
- Looking at our spine from the posterior way it will be vertically straight
- Excess of weight and other forces can make your spine alignment change.
- Spine has 3 natural curves on the spine called cervical curve, thoracic curve, and lumbar curve.
- The five regions of the spine are the 3 above plus the sacral and coccyx
- Helps support the weight from the upper body.
- Spine helps skull have an upright position to be able to walk.
- Spine protects spinal cords and nerves, and supports body to be able to stand up.
Connection to Evolution
- We started by walking on both legs and hands, climbing trees, etc
- Primates like chimpanzees aren't bipedal because their legs go to their inside making it difficult for them to walk on two legs.
- Chimpanzees pelvis aside from human's pelvis is longer and flatter says Eric Wayman.
- Their feet don't have arches like humans so their feet are more wide apart, and when they stand their feet get closer.
- The bridge between primates and humans started with 'Lucy' the first primate known who was bipedal, she could walk upright because her hips and knee joints were more human like.
- Lucy's knee could "lock" allowing the leg to be able to stand straight and make movement.
- Then primates started to change by getting a curved spine, a strong knee , a long leg and humans were created.
Bipedal Animals
Advantages
- Bipedalism brought advantages throughout the process of evolution since they could use their hands to carry things, or do other activities with their hands.
- Less energy is used since walking on four took more energy away.
- They got taller so they could get things easily, see their predators, look farther and in more directions, and they could get into deeper water.
- All of this advantages gave them more chances of survival.
- According to Alexander R N
- Run Bipedally
- Birds
- Many lizards at their highest speeds
- Cockroaches
- Hop Bipedally
- Kangaroos
- Birds
- Jerboas
Conclusion
Walking upright not only brought us advantages throughout time it brought us new chances of survival. It changed our physical appearance along with our way of life and the structure of our body.