human evolution from ape-like ancestors

Question 1

evidence

Answer 1

• A. fossil evidence (early hominins)
• B. genetic evidence (mtDNA)
• C. cultural evidence (tool making)

Question 2

A. fossil evidence

Answer 2

• teeth , lower jaws, facial and upper cranial bones
• femurs
• bone size
• shape
• markings left by muscles
• bipedalism
• brain size
• teeth (dentition)
• prognathism (jaw that sticks out)
• palate shape
• cranial (sagittal) and brow ridges

Question 3

advantages bipedalism

Answer 3

• pre-adapted bipedalism (free arms to climb)
• live in variety of areas
• see danger
• make tools (gather food)
• reduce risk of overheating

Question 4

disadvantage bipedalism

Answer 4

• backbone stress (no longer cantilever)
• shoulder blade no longer shock absorber
• narrowed birth canal

Question 5

knowledge of bipedalism

Answer 5

• foramen magnum further forward (apes back, fossil hominids middle, humans centre)
• shorter, broader pelvis
• S-shaped spine

Question 6

brain size

Answer 6

• increased :
• better co-ordination
• greater information processing
• development of speech

Question 7

teeth

Answer 7

• general decrease in size
• tooth enamel (thin in african apes , thicker later on)
• canine (early : larger and projected , late : smaller)
• diastema - gap (early : larger , late : not existent)

Question 8

prognathism and palate (dental arch)

Answer 8

• african apes (large, prognathous)
• australopithecines (similar to apes)
• african apes (rectangular)
• early hominins (U-shaped)
• homo sapiens (parabolic)

Question 9

cranial and brow ridges

Answer 9

• hominids (protruding)
• well-developed jaws
• african apes (very big)
• early hominins (well developed)
• later hominins (greatly reduced)

Question 10

diet change

Answer 10

• raw to cooked
• larger canines to smaller teeth
• jaws large and protruding to smaller jaws less prognathous
• cranial and brow ridges offer more muscles for chewing to absence of cranial and brow ridges less muscles

Question 11

B. genetic evidence

Answer 11

• nuclear DNA (humans share of 99.9% , apes share 96.9%, chimpanzees and apes share 98.8%)
• hominid mtDNA (how long ago separated)

Question 12

C. cultural evidence

Answer 12

• specialised physical features (dexterous hands)
• tool making (getting food , efficient hunting)
• tool evolution