Evolution

Question 1

Define: Biological Evolution

Answer 1

The transmission and change of genetic information (DNA, genes, alleles) from generation to generation.

Question 2

What is a “Hominin”?

Answer 2

A subfamily of the hominids (great apes) that include all living and fossil species belonging to the human lineage.

Question 3

What is a distinguishing feature of Hominins?

Answer 3

A distinguishing feature is bipedalism.

Question 4

Describe the general STRUCTURAL characteristics of Primates

Answer 4

• Prehensile (grasping) hands & feet w opposable thumb (gripping & object manipulation)
• Nails instead of claws (sensitive finger pads & allow better grip, grasping, touch)
• Forward-facing eyes (overlapping visual fields, binocular stereoscopic 3D vision enhances depth perception)
• Bony ridges (above eyes) to protect eyes
• Tendency to having erect upper body (associated with sitting and walking)

Question 5

Identify general PHYSIOLOGICAL and BEHAVIOURAL characteristics of primates

Answer 5

PHYS:
- Longer Gestation (pregnancy) periods than most mammals
- Typically have one young per pregnancy

• Longer periods of infant dependency and large parental investment. Additional nurturing increases survival rate

Question 6

Arboreal/Brachiation

Answer 6

Animals that live in the forest use their arms to swing from tree to tree. They have a freely rotating shoulder provided by the cone-shape of their ribs to accommodate this.

Question 7

Compare and Contrast “New World Monkeys” and “Hominins”

Answer 7

New World monkeys:
-prehensile tail (for balance)
-primarily quadrupedal
-widely separated nostrils.
-protruding canines
-thicker hair
-pronounced eye ridges

Hominins:
-bipedal
-larger cerebral cortex
-no tail
-finer hair
-reduced eye ridges
-reduced canines

Question 8

How does s-shaped spine help bipedalism?

Answer 8

brings the torso’s center of gravity over the hips. This shape acts as a shock absorber during walking and allows for more balance and stability when upright, minimizing the risk of injury or fatigue.

Question 9

what is the point of foramen magnum being central in bipeds?

Answer 9

balances the head directly over the spine. This reduces the need for strong neck muscles to hold the head upright, allowing for more efficient bipedal locomotion.