Bipedalism

Anatomy and Physiology 24-25, Ms. Naughton

Define Bipedalism

Walking on two feet.

Pros of Bipedalism?

Improved tool usage (hands) , less energy usage.

How many lumbar vertebrae do bipeds have?

5; allows for more movement , (hips can swivel when walking, more flexible)

How many lumbar vertebrae do quadpeds have?

4; less flexibility/mobility, swing both hips and legs when walking.

Describe the difference between a bipeds pelvic bone and a quadpeds pelvic bone.

A Biped has more compact, quad has more elongated.

How did homo sapiens evolve from chimpanzees based on toes/feet?

Chimpanzees had larger/more prominent big toes for grasping and climbing. Homo sapiens big toes were modified to be used for balance, more enlarged tarsals as well to help support weight.

Describe the evolution from human to chimpanzees based off femurs and WHY.

femur in humans is angled to allow for knee and feet to be under the bodies center, chimpanzees were straight.

Describe the modifications from quad peds to bi peds based on skull/foramen magnum

Bipeds - under the skull so they can look out while standing. Quad peds - further back so look out when on all fours.

Foramen Magnum

Opening in occipital bone; connects brain and spinal cord.