Primates

Question 1

Main sense in primates?

Answer 1

Shift from smell to vision as the primary sense.

Eyeball in eye socket for protection.
Forward facing eyes to give a better 3D view.

Question 2

Other features of primates?

Answer 2

Larger brains
Grasping hands for trees
Locomotion is lower limb dominated with a lower centre of gravity.

Question 3

Adaptations of primates to trees?

Answer 3

Equal length limbs, meaning all 4 limbs can be used for walking. Well developed grasping hands and tail for balance.

Large shoulder socket to allow broad range of movements between trees.

Question 4

Adaptations of primates for land?

Answer 4

Equal lenght limbs to avoid strain.
Bipedal when longer lower limbs, but rare.
Stronger hands and feet for running, or heavier animals.

Question 5

How are primate hands adapted for climbing?

Answer 5

Manipulative abilities related to:

• finger articulation
• length of fingers
• thumb
• tactile sensors.

Opposable thumb means you can internally rotate the thumb.

OWM and Apes have full rotation.

Question 6

Feeding in primates?

Answer 6

Teeth - incisors are for preparation of food for mastication.
Molars masticate and prepare the food for digestion.

Cheek pouch - stores food for later. Can also feed friends. Upper limbs can also be used to store food.

Question 7

Eyes in primates?

Answer 7

Cell composition of retina - trichromacy - is almost unique to primates among mammals. Three types of photopigments in cone cells.

Nocturnal species have larger eyes.

Tarsier has such big eyes that doesn’t have space for muscles to move the eyes and instead has to move its head.

Two eyes allow for 3D perception. Useful to identify ripe fruit and mates.

Question 8

Are monkeys a monophyletic group?

Answer 8

No, Apes aren’t monkeys.

Question 9

Features of apes?

Answer 9

All lack tails 
Large brains 
Longer arms than legs 
Social systems 
Tropical rain forests 
Some have knuckle walking - quadrupedal

Question 10

Describe gibbons?

Answer 10

Live in forests of SE Asia 
Small 
Monogamous 
Important seed dispersers 
Territorial with vocal displays

Most endangered primate. The main reasons for this are habitat loss and degradation, hunting and illegal trade.

Question 11

Describe orrangutans?

Answer 11

Massive sexual dimorphism (40-90kg). 
Highly aboreal 
Eat fruit, leaves, bark and small vertebrates. 
8-9 interbirth interval 
Tool users 

Exploded polygyny - single male defends a group of females and their offspring but the females don’t live as a group and are spread over up to 5 km^2.

Question 12

Describe gorillas?

Answer 12

Up to 200kg, largest primate.

Eat fruits and leaves.
Climb trees

Polygyny - females migrate across groups and the male leaves before maturity

Question 13

Describe chimpanzees?

Answer 13

Eat fruits, leaves, flowers, insects and animals.

Female intergroup migration.
Male 40-60kg
Female 20-50kg

Question 14

Human hand?

Answer 14

Power grip - all fingers and thumb

Precision grip - thumb and index finger

Question 15

Bipedalism requirements?

Answer 15

Need to have the head balanced and upright by moving the hole which connects the skull to the back.

Pelvis is an organ support.

Longer legs to increase stride length.

Stronger organisation of the back.

Question 16

Bipedal stature advantages?

Answer 16

Can transport items as not using hands for walking
Reach higher branches
Maximise exposure to wind, lower to sun. Thermoregulation.

Question 17

Ape mating systems?

Answer 17

Orangutan & Gorilla:
Dominant male has access to multiple females. Extreme sexual dimorphism.

Chimpanzee:
Male hierarchy.