ANTB14H3 Lecture Notes - Lecture 6: Foramen Magnum, Vertebral Column, Quadrupedalism
Document Summary
Y-5 molar and lack of a tail is traits for hominids. Makes it difficult to sort out phylogenetic traits. Relative brain size = size of brain/size of body. The organization and stuff is all important rather than just the size. Increased surface area most likely associated with increased intelligence. Morphological differences between bipedal hominins and quadrupedal apes. The knees of a. afarensis are more like the knees of modern humans than the knees of chimpanzees. Consider the lower end of the femur, where it forms one side of the knee joint. In chimpanzees, this joint forms a right angle with the long axis of the femur. In humans and australopithecines, the knee joint forms an oblique angle, causing the femur to slant inward toward the centerline of the body. This slant causes the knee to be carried closer to the body"s centerline, which increases the efficiency of bipedal walking. Wider angle between tibia and femur (greater than 90 degrees)
