Lecture 15

Question 1

Hominin

Answer 1

Members of the human lineage (Homo, Australopithecus, Paranthropus, etc.).

Question 2

Hominidae

Answer 2

“Great apes” family (humans, chimps, gorillas, orangutans).

Question 3

Catarrhines

Answer 3

Old World monkeys and apes (Africa/Asia).

Question 4

Cercopithecoids

Answer 4

Old World monkeys (e.g., baboons).

Question 5

Obligate bipedalism

Answer 5

Exclusive, habitual upright walking.

Question 6

Foramen magnum

Answer 6

Hole in the skull where the spinal cord enters.

Question 7

Valgus knee

Answer 7

Femur angles inward, aligning knee under the hips.

Question 8

Lumbar lordosis

Answer 8

S-curve in the spine (vs. C-curve in apes).

Question 9

Pelvic bowl

Answer 9

Short, broad pelvis with repositioned gluteal muscles.

Question 10

Arched foot

Answer 10

Longitudinal/transverse arches for shock absorption.

Question 11

Non-opposable hallux

Answer 11

Big toe aligned with other toes (not grasping).

Question 12

Humero-femoral index

Answer 12

Ratio of arm-to-leg length (longer legs in bipeds).

Question 13

Postural Feeding Hypothesis

Answer 13

Bipedalism evolved to reach fruit in trees.

Question 14

Thermoregulation Hypothesis

Answer 14

Upright posture reduces sun exposure.

Question 15

Savanna Hypothesis

Answer 15

Drier habitats selected for bipedalism.

Question 16

Vigilance Hypothesis

Answer 16

Bipedalism aids predator spotting in tall grass.

Question 17

Energetic Efficiency Hypothesis

Answer 17

Bipedalism saves energy over quadrupedalism.

Question 18

Sahelanthropus tchadensis

Answer 18

Probable early hominin (7–6 Ma, Chad); anterior foramen magnum.

Question 19

Orrorin tugenensis

Answer 19

Early hominin (6–5.7 Ma); thick femoral neck suggests bipedality.

Question 20

Ardipithecus ramidus

Answer 20

“Ardi” (4.4 Ma); mix of bipedal and arboreal traits.

Question 21

Australopithecus anamensis

Answer 21

Earliest definite biped (4.2–3.8 Ma).

Question 22

Australopithecus afarensis

Answer 22

“Lucy” (3.9–2.9 Ma); clear bipedality (valgus knee, arched foot).

Question 23

Australopithecus africanus

Answer 23

Gracile australopith (3.3–2.1 Ma); bipedal pelvis, small brain.

Question 24

Paranthropus aethiopicus

Answer 24

Robust hominin (2.7–2.3 Ma); sagittal crest/flared zygomatics.

Question 25

Paranthropus boisei

Answer 25

“Nutcracker Man” (2.3–1.3 Ma); massive molars.

Question 26

Paranthropus robustus

Answer 26

Robust hominin (2–1 Ma); sexual dimorphism.

Question 27

Gracile vs. Robust

Answer 27

Australopithecus (smaller teeth) vs. Paranthropus (heavy chewing adaptations). Post Crania: Different, Crania: Same

Question 28

Positional repertoire

Answer 28

Mixed arboreal/bipedal locomotion (e.g., curved fingers + bipedal pelvis).

Question 29

Laetoli footprints

Answer 29

Fossilized footprints (3.7 Ma, Tanzania).

Question 30

Sagittal crest

Answer 30

Bony ridge on skull for chewing muscles.

Question 31

Bicondylar angle

Answer 31

Angle between femur shaft and knee (valgus knee).

Question 32

Double arch (foot)

Answer 32

Longitudinal + transverse arches in human-like feet.