Primates

Question 1

How does homology aid us in the study of primates?

Answer 1

Shared traits acquired by a common ancestor. Gives more insight into anatomy and behaviour of ancestors through living primates, as opposed to others eg. reptiles.

Question 2

How does analogy aid us in the study of primates?

Answer 2

We can see how evolution shapes adaptations in response to different selection pressures.

Question 3

How do primates reflect the ‘mosaic nature of evolution’?

Answer 3

As primates were spread across nations, 50-60mya, and faced different environmental and selective pressures they have evolved different and not in a linear fashion.

Question 4

What are ancestral traits shared between primates and humans?

Answer 4

Ancestral traits are those inherited from a common ancestor eg. being vertebrates, homeothermic, and having hair

Question 5

What are derived traits?

Answer 5

Newly arising traits, one that a current organism has, and a previous one didn’t

Question 6

What are some distinguishing traits of primates?

Answer 6

Prehensile hands, opposable big toes, stereoscopic vision, reduced olfactory reliance, nails, unspecialised teeth, large brain, small litter size, and prolonged dependency of young.

However, none of these are unique to primates and not all primates possess these.

Question 7

What are some examples of human traits being different from that of the distinguishing traits of primates?

Answer 7

Prehensile hands and feet; out feet aren’t - bipedality

Opposable big toes; we don’t grasp with our toes…

Stereoscopic vision; We have binocular (overlapping), eyes rotated to front to see in 3D and colourful vision

Question 8

What are some examples of distinguishing traits of primates being shared with human traits?

Answer 8

Reduced olfactory reliance; Increased reliance on vision

Nails v claws; nails to protect sensitive skin on fingers and toes

Unspecialised teeth; Not needed for warfare or dietary reqs.

Question 9

What are the different group of primates?

Answer 9

Prosimi, Tarsioidea, Anthropoidea

Question 10

What are some distinguishing traits of prosimians?

Answer 10

PO Bar only

Wet nose and split lip

Dental comb

Question 11

What are two examples of prosimians and their distinguishing traits?

Answer 11

Lemurs (Madagascar): Underwent adaptive radiation (complete isolation from primates elsewhere), lower body temp and metab rate to survive extreme dietary reqs.

Ring-tailed lemur: Highly gregarious, greater reliance on vision yet still high reliance on olfactory system, scent mark vegetation and scent mark tails for territory.

Question 12

What are some distinguishing traits of tarsioids?

Answer 12

PO bar and partial plate

Dental formula 2133/1133

Elongated tarsal bones of foot

Question 13

What are some distinguishing traits of Anthropoids?

Answer 13

PO bar and plate

Nails on all digits

Question 14

What are some distinguishing traits of the platyrrhini infraorder?

Answer 14

Flat nose

Widely separated nostrils

Found in South and Central America

Question 15

What is the extant superfamily in the infraorder platyrrhini? and some distinguishing traits

Answer 15

Cebidae (capuchins); Relatively large body sizes, live socially with varied diet, have culture and traditions.

Question 16

What are the two extant superfamilies in the infraorder catarrhini?

Answer 16

Cercopithecoidea and hominoidea

Question 17

What are some distinguishing traits of the cercopithecoidea superfamily?

Answer 17

Nostrils close together

Non-prehensile tail

Bilophodont molars

Question 18

What are some distinguishing traits of the Hominoidea superfamily?

Answer 18

Tail absent

Antero/posteriorly flattened thorax

Some Y-5 Molars

Question 19

What are the three families of the Hominoidea superfamily?

Answer 19

Hylobatidae, pongidae, and hominidae

Question 20

What is the distinguishing trait of the hylobatidae family?

Answer 20

Gibbons; Brachiation as main method of locomotion

Question 21

What are some distinguishing traits of the pongidae family?

Answer 21

There are no unique traits.

Gorilla; fist or knuckle walking, sparse body hair, found in borneo and sumatra, quadrumanous

Question 22

What are some distinguishing traits of the hominidae family?

Answer 22

Humans; Knuckle walking or bipedal, mixed sex communities

Question 23

What is behavioural ecology?

Answer 23

Why different species behave in different ways. A product of natural selection resulting in increased adaptation to ones habitat.

Question 24

What is the effect of socioecology on behaviour?

Answer 24

Ones social system is the response to ecological conditions; availability and distribution of resources

Question 25

Effect of survival fitness on behaviour?

Answer 25

There is a suite of adaptations to the ecological and social environment; food, co-ordinate male, offspring, avoiding parasites and predators

Question 26

What are the costs and benefits of large groups?

Answer 26

Benefits: Lower risk of predation (safety in numbers) and better defence of territory Costs: Increased comp for resources, increased likelihood of disease, and increased conspicuousness

Question 27

How is the optimal group size achieved?

Answer 27

Size reflects the balance of costs and benefits; influenced by social and ecological factors Female #'s are limited by food due to high metabolic costs of gestation and lactation Male #'s are limited by # of females Ecological pressures influence distribution of females and males distribute themselves to maximise access to females

Question 28

What is the relationship between specialisations and diet?

Answer 28

Dietary specialisations drive other specialisations such as teeth and body size. Insectivores are smaller than frugivores while are smaller than folivores; differences in size related to differences in energy reqs

Question 29

What are some specalisations of primates than have come about as a result of their diet?

Answer 29

Digestive tract; primates are unable to digest cellulose, and as a result have developed a digestive tract with a microorganism present to digest cellulose Brain size; frugivore larger than folivore. Need to remember location and phenological status of fruit trees

Question 30

Is there a link between the distribution of resources and territoriality?

Answer 30

Yes Clumped resources; ability to be defended hence high territoriality Even distribution; egalitarian relationship, difficult to defence

Question 31

What are three types of group distributions? and what is their purpose

Answer 31

Scramble; in an even distribution of resources, as the amount of food per individual is inversely proportional to group size Contest; found in clumped resource distributions, aggressive competition over defensible resources Fission-fusion; split into sub-groups to later reform, unequally dispersed food, used to reduce food competition through dispersal of small foraging groups

Question 32

What are some types of primate social organisation?

Answer 32

Solitary Pair-bonded Polyandry (one female) Polygyny (one male) Polygynandrous (multi-male)

Question 33

What is a solitary social organisation?

Answer 33

Galago or orangutan Males defend home ranges that ecompass home ranges of several females

Question 34

What is pair-bonded (monogamy) social organisation?

Answer 34

Gibbons Females are dispersed and males associate with one Often territorial

Question 35

What is a polyandrous social organisation?

Answer 35

Marmoset, callitrichids Several males associate with one female

Question 36

What is a polygynous social organisation?

Answer 36

Gorilla Resident male monopolises reproduction to increase their own reproductive success Often leads to infanticide; new male kills all offspring not related to him

Question 37

What is a polygynandrous social organisation?

Answer 37

Baboons and Chimpanzees Multiple males and females. Often fission-fusion. Often promiscuous - >1 partner to increase reproductive success

Question 38

Is there a correlation between sexual dimorphism and polygyny?

Answer 38

Pronounced body dimorphism is suggestive of high male-male competition Gibbons are monogamous; male canine = female canine Gorillas are polygynous; substantial dimorphism in canine length Humans have mild polygyny; less dimorphic than pre-homo fossil hominins

Question 39

Is there a relationship between testis size and mating system?

Answer 39

Yes Promiscuous mating have much larger testes than single male groups. Competition over mates and sperm competition.