Which of these statements best summarizes the relationship between the birth canal and brain size during the course of hominin evolution?
A. Natural selection has favored a tendency toward decreased brain size and a reduction in the size of the pelvic opening throughout hominin evolution.
B. Brain size has become more important than bipedalism over the course of hominin evolution, and the pelvic opening has continually expanded to compensate for larger brains.
C. Natural selection has struck a balance between the structural demands of upright posture in bipedalism, which limits the expansion of the pelvic opening, and the tendency toward increased brain size.
D. The birth canal has become narrower throughout hominin evolution, even as brain size has continued to increase.
E. The human pelvic opening has continually expanded to allow for increased brain size, but the upright posture of bipedalism has been unaffected by these structural changes.
Question 2
Oldowan tools were manufactured by
A. chipping flakes off a core.
B. chipping blades off a prepared core.
C. using deer antlers to pressure-flake a core.
D. striking steel against a stone core.
E. grinding a coarser stone against a softer one.
Use of fluorescent molecules by Lowenstein and colleagues to determine the size of gap-junction chan
A Split-Brain Experiment
Size of Particles
Neurons in the outer layers of the brain
The Addicted Brain
Coup and Contrecoup Movement of the Brain