Origin of Early Hominins

Question 1

Where was the earliest Hominin found?

Answer 1

Africa “Cradle of humanity

Question 2

When was the first homin’s remaind dated?

Answer 2

4-5 MYA

Question 3

What were the two earliest hominins found?

Answer 3

• Australopithecus afarensis - (earliest)
• Australopithecus africanus - (next earliest)

Australopithecus are different to Homo

Question 4

Describe relation of Australopithecus to modern humans

Answer 4

Direct line of humans

Question 5

What was the second hominin discovered after the Australopithecuses?

Answer 5

Paranthropus

Very similar to Australopithecus

Question 6

Describe the differences in the skull structure between Australopithecus/Paranthropus and Modern humans

6 key differences

Answer 6

Australopithecus/Paranthropus had
* Smaller cranium
* Large zygomatic arches
* Big brow ridges
* Very define crest on skull
* More rectangular arrangement of teeth
* More posterior positioned foramen magnum

in comparison to modern humans

Question 7

What do larger zygomatic arches and crest on skull suggest for these early hominins?

Answer 7

• Had large jaw muscles that needed to get through zygomatic arches.
• Crest allowed for better muscle attachment.
• Had large bite force.
• Diet consisted of robust tough and fibrous foods

Question 8

Describe the differences in the skull structure between Australopithecus/Paranthropus and other primates

Answer 8

Australopithecus/Paranthropus had
* larger cranium (higher intelligence)
* More parabolic arrangement of teeth
* More anterior positioned foramen magnum (better bipedalism)

in comparison to other primates

Question 9

What does size of cranium suggest for the early hominins?

Answer 9

• More intelligent than other apes
• Much less intelligent than modern humans

Question 10

State some key lifestyle characteristics of Australopithecus/Paranthropus

4

Answer 10

1. Sexual dimorphism (physical difference between males and females)
2. Predicted that one dominant male lived with group of females
3. Diet of robust fibrous foods
4. Bipedal

Question 11

What does the position of the foramen magnum in early hominins suggest about their bipedalism?

Answer 11

• Were bipedal for at least 50% of the time
• Still relied on using all 4 limbs to quickly manuever
• Had a prominent hunch when walking upright

Question 12

Describe the differences in the limb structure between Australopithecus/Paranthropus and Modern humans

Answer 12

Australopithecus/Paranthropus had
* Long arm to leg length ratio
* Opposable big toe

in comparison to modern humans

Question 13

What do the limb structures of the early hominins suggest about their lifestyle?

Answer 13

• Still sometimes used 4 limbs to walk
• Could climb trees well (opposable big toe)
• May have lived/slept in trees at night

Question 14

Describe the differences in the pelvic structure between Australopithecus/Paranthropus and Modern humans

Answer 14

Australopithecus/Paranthropus had
* Smaller gap in pelvis
* Less bowl shaped

in comparison to modern humans

Question 15

What does the pelvic structures in early hominins suggest about them?

Answer 15

Gave birth to small headed babies = less intelligent