The Beginnings of Human Evolution

1			Australopithecus afarensis, known as a gracile Australopithecine, was present in East Africa between 4 - 2.9 mya. In general the Australopithecines present a more ape-like morphology than later Homo. What morphological features of the skull, paying particular attention to the face and teeth, can you discern that reflect our ape ancestry?
			A)	large protruding face (facial prognathism), projecting canines, small brain
			B)	small incisors, rounded frontal
			C)	rounded frontal, projecting brow ridge, small brain
			D)	large projecting canines, small cheek teeth
			E)	small brain, reduced facial prognathism, post orbital constriction

Australopithecus afarensis SC 012 Ergaster (184.0K)

Bonobo (Pan paniscus) SC 123 Bonobo Skeassem x (62.0K)

2			Perhaps the most well known of Australopithecine fossils is the skeleton of Lucy (AL 288-1). Lucy is a female specimen of A.afarensis, and was approximately 3'3" tall and weighed around 60 lbs. What aspects of the postcranial skeleton of Lucy (AL 288-1) display an ape-like morphology?
			A)	short, stocky limbs; wide, flaring pelvis
			B)	curved phalanges, long legs, divergent big toe
			C)	relatively long arms, barrel shaped rib cage, curved phalanges
			D)	cone shaped rib cage; curved phalanges; relatively long arms
			E)	wide, flaring pelvis; curved phalanges; cone shaped rib cage
3			What is the significance of the ape-like morphology of the postcranial skeleton?
			A)	indicates Lucy is closer related to chimpanzees than to Homo
			B)	indicates that A. afarensis was fully terrestrial
			C)	suggests Lucy was a knuckle walker
			D)	indicates that A. afarensis was an evolutionary dead end
			E)	indicates that A. afarensis still retained the ability to climb trees
4			At the site of Laetoli, Tanzania, fossilized footprints were discovered that were dated to 3.8 mya and associated with A. afarensis. What is the significance of this discovery?
			A)	demonstrates that they had a divergent big toe
			B)	indicates monogamous family groups
			C)	large projecting brow ridges
			D)	dish shaped face
			E)	presence of post-orbital constriction

Australopithicus africanus (Front View)	Australopithicus africanus (Side View)
BH_007_036 (39.0K)	BH_007_009 (43.0K)

5			Sts 5, dubbed Mrs. Ples, was discovered at Sterkfontein, South Africa by John Robinson and Robert Broom. A. africanus was present between 3 - 2.5 mya and is a potential descendant of A. afarensis. What features of the face differentiate A. africanus from the earlier A. afarensis?
			A)	shorter face with less facial prognathism
			B)	longer face with increased facial prognathism
			C)	large projecting brow ridges
			D)	dish shaped face
			E)	presence of post-orbital constriction
6			What features of the dentition of A. africanus differentiates this species from A. afarensis?
			A)	increased prognathism, larger anterior dentition
			B)	larger anterior dentition, decreased prognathism
			C)	presence of a diastema, increased canines
			D)	reduced anterior dentition, decreased prognathism
			E)	decrease prognathism, presence of a diastema
7			Can you see any differences in the zygomatic bone between the two Australopithecines?
			A)	reduced in A, africanus
			B)	long and strongly built in A. afarensis
			C)	short but strongly built in A. africanus
			D)	long and strongly built in A. africanus
			E)	short and strongly built in A. afarensis
8			The fact that A. africanus's dentition was less specialized implies that there diet was:
			A)	more carnivorous
			B)	more vegetarian
			C)	based on fruit
			D)	more omnivorous
			E)	highly marine based
9			What morphological features indicate the similarity of A. africanus to early Homo?
			A)	increased cranial capacity
			B)	rounded basicrania
			C)	greater basicranial flexion
			D)	decreased anterior dentition
			E)	increased cranial capacity, greater basicranial flexion AND decreased anterior dentition

Australopithecus boisei (Front View)	Australopithecus boisei (Side View)
BH_015_C_001 (29.0K)	BH_015_C_008 (32.0K)

10			The fossil OH 5 or Olduvai Hominid 5 was discovered by Mary and Louis Leakey in 1959 and given the name Zinjanthropus. This species, considered a robust Australopithecine, is also known as Paranthropus boisei. Present exclusively in East Africa between 1.8 - 1.2 mya, what features of the face and cheekbones indicate A. boisei as a robust Australopithecine?
			A)	dish shaped face; strong forward projecting zygomatic arch
			B)	dish shaped face; reduced zygomatic arch
			C)	long and narrow face; decreased facial prognathism
			D)	strong forward projecting zygomatic arch; long and narrow face
			E)	long and narrow face; reduced zygomatic arch
11			Australopithecus boisei continues a similar dental pattern to A. africanus, with a reduction in the size of the anterior dentition (canines and incisors) but has an even greater emphasis on the cheek teeth with the premolars almost completely moralized. What can this dental pattern along with the robust nature of the mandible and presence of a sagittal crest tell you about the diet of A. boisei?
			A)	they consumed large amounts of meat
			B)	they focused on leaves
			C)	they ate harder more fibrous vegetal foods
			D)	they ate large amounts of fish
			E)	they ate harder nuts and seeds

Australopithecus robustus (Front View)	Australopithecus robustus (Side View)
BH_003_1 (36.0K)	BH_003_8 (37.0K)

12			This robust Australopithecine species is found in South Africa between 1.8 - 1.2 mya. Like Australopithecus boisei some authorities refer to this specimen as Paranthropus to indicate the close kinship shared by the robust Australopithecine forms and separating them from the gracile Australopithecines. What features of the face does Australopithecus robustus share with Australopithecus boisei?
			A)	reduced facial prognathism
			B)	wide, flaring zygomatic arches
			C)	reduction of the cheek teeth
			D)	dish shaped face
			E)	wide, flaring zygomatic arches and dish shaped face
13			Are there characters of the cranium that are similar between the two robust species?
			A)	sagital crest; high frontal
			B)	occipital bun; high frontal
			C)	high frontal; pronounced postorbital constriction
			D)	large projecting brow ridges; occipital bun
			E)	pronounced postorbital constriction; sagital crest
14			If you look at the posterior portion of the skulls are there any similarities?
			A)	presence of a nuchal crest
			B)	sharply angled occipital
			C)	occipital bun
			D)	elongated occipital
			E)	rounded occipital
15			If A. robustus had a similar fibrous, vegetal diet as A. boisei what would you expect the anterior dentition to look like?
			A)	reduced size of cheek teeth
			B)	increased anterior dentition
			C)	reduced anterior dentition
			D)	large projecting canines
			E)	reduced size of cheek teeth AND increased anterior dentition
16			When examining both the robust and gracile forms of Australopithecines is there any feature that suggests the robust forms are closer related to the Homo lineage?
			A)	large check teeth
			B)	increased cranial capacity
			C)	postorbital constriction
			D)	wide dished face
			E)	large check teeth AND postorbital constriction
17			Why is A. africanus considered closer related to early Homo than A. robustus or A. boisei?
			A)	share similar diet
			B)	increased cranial capacity
			C)	the facial and dental structure
			D)	they are both bipedal
			E)	the shape of the pelvis