Human Evolution

Question 1

Humans vs. Chimpanzees

Answer 1

• protein sequences are 98.5% similar
• 6% of human genes are not found in chimps
• replicate copies of some genes in humans not found in chimps

Question 2

What are “hominins”?

Answer 2

all species on the human side of the family tree after the split from the branch that became modern chimps

Question 3

When did hominins diverge from apes?

Answer 3

by 6.0 ma

Question 4

Earliest Hominin?

Answer 4

Sahelanthropus

• bipedal and small brained

Question 5

What is the foramen magnum?

Answer 5

the hole at the base of the skull through which the spinal chord passes

Question 6

What does the position of the foramen magnum at the base of the skull to us?

Answer 6

• directly beneath says erect, vertical posture and bipedalism
• from the rear says horizontal posture

Question 7

Age of Australopithicines

Answer 7

~4.0 to 1.8 Ma

• bipedal with small brains
• restricted to southern and eastern Australia
• Lucy and Taung Child

Question 8

Dental Arcades

Answer 8

• rectangular with large canines: ape-like
• semi-parabolic with smaller canines: australopithecines
• parabolic with greatly reduced canines: homo sapiens

Question 9

Laetoli Ash

Answer 9

• Tanzania

- ~3.6 Ma fossil footprints of bipedal australopithecines

Question 10

Genus Homo

Answer 10

split from australopithecines approx. 2.5 Ma

• developed crude stone tools
• medium-sized cranial capacity and bipedal

Question 11

Homo Erectus

Answer 11

~ 1.8 ma

• large brained (at high metabolic cause, increase caloric diet), bipedal
• more carnivorous diet (encouraged cooperation and hunting in groups)
• expanded migration to Africa, Middle East, and South Africa

Question 12

Homo Neanderthalensis

Answer 12

230 - 30 Kyr

• expanded to Europe, Middle East, and Central Asia
• cold adapted with heavy build and muscular bodies
• some evidence of burial practice

Question 13

Anatomically Modern Humans

Answer 13

200 thousand years ago

• acceleration of cultural evolution evident through cave paintings (40 Kyr)

Question 14

Homo Floresiensis

Answer 14

found on Flores Island, Indonesia

• 44,000 - 13,600 years ago
• “hobbits” (3 ft tall)
• cranial capacity is less than chimps but also due to relative size of the bodies

Question 15

Trends in Human Evolution

Answer 15

1. ) Brain size (increase)
2. ) body size (increase)
3. ) Bipedalism
4. ) dental arcade becomes more parabolic with reduced canines
5. ) less body hair

Question 16

Advantages to being Bipedal

Answer 16

• carrying behavior
• reduction of overall heat stress (more surface area therefore easier to cool down)
• better vision
• energy efficient for travelling
• possible defense against predators (hands to carry weapons and fight them off)