0. Human Changes Over Time HS

Question 1

List the characteristics that make a mammal.

Answer 1

A variety of teeth
One single lower jawbone attached directly to the skull
Three bones in their middle ear
Various amounts of hair or fur on their bodies throughout their lifetime
Mammary glands that produce milk

Question 2

List the characteristics that all primates share.

Answer 2

Prehensile or grasping hand
Opposable thumb(s)
Flat finger nails instead of claws and sensitive tips of digits
Large, forward facing eyes.
Large brain volume in comparison to body size

Question 3

List the characteristics that hominoids share.

Answer 3

No tails
Semi-erect moving posture (knuckle walkers)

Question 4

List the characteristics of hominins.

Answer 4

Bipedalism
Loss of opposable big toe/thumb
Precision grip
Increased brain case size
Increased brain to body ratio
Parabolic jaw and uniform teeth
Longer gestation and care of young

Question 5

State the morphological changes in hominins related to bipedalism

Answer 5

Humans have shorter arms in comparison to leg length than other primates and hominoids.
Our pelvis has become more bowl like than our ancestors
Human femurs have angled inwards to offer more support when walking.
Loss of opposable thumb on foot
Larger heel bone
Curvature of the spine

Question 6

Describe the location of the foramen magnum in Homo sapiens.

Answer 6

The foramen magnum is central to the base of the skull in Homo sapiens this means that the head is better balanced allowing for bipedalism

Question 7

State the advantages of bipedalism

Answer 7

Hands free
Tool-making
Precision grip
Reaching higher food
Scanning for predators.