Anthro1 Midterm

Why do we study primates?

1. homology: humans share inherited similarities in anatomy and behavior

2. analogy: primates provide models for how selection shapes adaptations in environments occupied by our ancestors

What is a primate? Characteristics?

• grasping and sensitive hands and feet (opposable big toe)

• nails instead of claws

• hind-limb driven locomotion

• forward-facing eyes encased in bone

• enhanced vision, less reliance on olfaction (smell)

• relatively large brain

What is a primate? Characteristics of offspring

• long gestation period

• small litters

• long juvenile period

• long lifespan

• increased dependence on learning and behavioral flexibility

primate teeth

• All primates have the same kinds of teeth

  • incisors (I), canines (C), premolars (P), molars (M), usually in the order I-C-P-M

    • configuration of teeth is usually the same for both the upper (maxilla) and lower (mandible) jaws

    • teeth are bilaterally symmetrical (left and right sides of the mouth are the same)

primate teeth formula - strepsirrhines

2.1.3.3 /

2.1.3.3

primate teeth formula - humans and catarrhines

2.1.2.3 /

2.1.2.3

primate location

• tropical animals, mainly forest-dwelling arboreal animals

• modern day range: asia, Africa, and south america

• ancient day range: southern europe and north america

• primates have never been found on australia or antartica

primate phylogeny: two starting branches

Strepsirrhines vs. Haplorrhines

primate phylogeny: Strepsirrhines two major groups

lemurs v. lorises

primate Phylogeny: Haplorrhines two major subgroups

tarsiers v. anthropoid primates (Simiiformes): monkeys, apes, humans

primate phylogeny: Anthropoidea, two major groups

platyrrhini (new world monkeys) v. Catarrhini (Old world anthropoids)

primate phylogeny: Catarrhini two groups

cercopithecoidea (Old world monkeys) v. Hominoidea (apes and humans)

Compare strepsirrhines vs haplorrhines: primate suborders

strepsirrhines:

• lemurs: live on Madagascar

• lorises: live in parts of South Asia

haplorrhines:

• includes tarsiers, monkeys, apes, and humans

strepsirrhines - key characteristics

• tooth comb

• tapetum lucidum (reflective eye covering)

• rhinarium (wet nose)

• scent glands

strepsirrhines - key characteristics SPECIFIC EXAMPLES

• lorises and pottos of Africa and asia: live in solitary and are nocturnal

• bushbabies of Africa

• lemurs of madagascar

tarsiers

• Haplorrhines —> more specifically tarsiiformes

• small, nocturnal, insectivorous, and carnivorous

• Southeast Asia

• grooming claws

*tarsiers are most closely related to monkeys and apes (simiiformes)

anthropoidea: two branches

platyrrhini (new world monkeys) v. Catarrhini (old world anthropoids)

Catarrhini (old world anthropoids) - two subgroups

cercopithecoidea (old world monkeys) v. hominoidea (apes and humans)

Hominoids (humans, apes)

• subgroup of catarrhines

• distinct from tarsiers and all other primates

• larger brain and body size

• longer life span

• longer interval between births

• tendency towards upright posture

• shorter and less projecting face and muzzle

• no tail

• gorillas chimps and adult male orangutans spend considerable time on the ground

Great Apes - Specific examples

• catarrhines —> hominoidea (oidea meaning without tails)

• orangutans, gorillas, chimpanzees

lesser smaller apes

• gibbons and siamangs

  • catarrhines

catarrhines - old world monkeys - key traits

• sharp-nosed catarrhines, nostrils face downward

• live in africa and asia

• no prehensile tails (think apes)

• all diurnal

• some arboreal, some terrestrial

• broad habitat range

• Dental formula: 2.1.2.3 / 2.1.2.3

Platyrrhines - New World Monkeys key characteristics

• flat, wide noses, nostrils turned to sideways

• many have prehensile grasping tails

• live in forests of central and south america

• arboreal and tropical forests

• quadrupedal

• dental formula: 2.1.3.3

• mainly diurnal

cercopithecinae subfamily (Cercopithecoidea)

• examples: baboons, macaques, vervets, mangabeys

• Old world monkeys

• narrow nose, downward nostrils, non-prehensile tail

• sub group of catarrhines

• mostly in Africa

• 23 species of macaques in Asia

• diversity in diet, size, habitat, social and mating strategies

• most common form of social organization is multiple adult males, multiple adult females, and offspring

colobinae subfamily

• colobus leaf monkeys and langurs

• found in asia and africa —> Old world monkeys

• primarily leaf and seed eaters

• arboreal

• polygnous MFF common

• infanticide observed

spider monkey

• platyrrhine (new world monkey), has prehensile tail

family atelidae

• howler monkeys, spider monkeys, woolly monkeys and muriquis

• largest platyrrhines —> new world monkeys

• some convergence with apes

• suspensory climbers

family cebidae

• capuchin monkeys and squirrel monkeys

  • large brain : body size

• owl monkeys are nocturnal

• callitrichinae:

  • 2-1-3-2 dental formula; claws

  • pair bonded marmosets and tamarins, cooperative breeding usually give birth to twins

capuchin monkeys

• widely distributed accross central and south america

  • genus cebus at least 4 species

  • genus sapajus (at least 8 species)

orangutans

• catarrhine —> hominodea

• confined to the Indonesian islands

• marked sexual dimorphism is evident

• least social of great apes

• 80% of their habitat has been destroyed

gorillas

• catarrhine —> hominodea

• 3 subspecies: western lowland, eastern lowland, and mountain gorilla

• exhibited marked sexual dimorphism

• spend little time in trees, usually they hang out on the ground eating plants leaves bark, fruits, etc

• live in troops of males and females with offspring

Chimpanzees

• catarrhine —> hominodea

• belong to genus pan (they are related to bonobos)

• diet is omnivore in nature

• sexual dimorphism is proportionally the same as in humans

• social organization is relatively well known—with communities of about 50 that regularly split into smaller groups and exhibit dominance relationships

• very vocal, greet each other with gestures, facial expressions and calls

Bonobos

• Belong to species Pan Paniscus

• adult males weight 95 lbs (smaller than chimps)

• communities are female centered, peace loving, and egalitarian

• sex is used to avoid conflict

bonobos v. chimps (differences)

• bonobos: pink lips, dark faced infants

• chimps: light faced infants

primate diets: insectivores

• small body size

• sharp cusps on teeth

• high sharp crests of molar teeth

• simple digestive system, short gut

examples: tarsieres and tamarins

primate diets: folivores

• large body size

• small incisors

• sharp shearing crests or molars

• enlarged, well-developed (specialized) digestive systems

examples: colobus, mountain gorilla, vervets, B&W bolobus, langurs

primate diets: frugivores

• medium body size

• large broad incisors

• low cusped relatively flat molars

• relatively large digestive system but not specialized like that found in folivores

example: chimps

primate diets: gummivores

• relatively small body size

• long, robust incisors

• claws in some

• long gut

example:

tamarins

primate territoriality

• some primates are less territorial —> meaning their home ranges overlap

primate territoriality - pros v cons

• cost: must defend the area

• benefits: can protect limited resources

primate predation:

• small terrestrial primates are most susceptible

  • terrestrial primates evolved larger body size and larger group size

    • south american forests, lots of felines and raptors —> no terrestrial primates

    • asia: few felines and raptors —> smaller terrestrial primates

primate defense against predators

• fleeing or taking cover

• vocalizations

  • ex: vervet monkeys

• interspecific associations (teaming up with animals of other species)

• increased group size

  • detection: more eyes to see predator

  • deterrence: mobbing behavior

  • dilution: lowers individual risk of death

• baboon

• narrow nose so catarrhine

• has a tail so Cercopithecoidea

• Aye aye

  • strepsirrhine —> lemur

• howler monkey

• haplorrhine —> platyrrhine new world (because it has a tail)

pygmy marmoset

• haplorhine —> platyrrhine (because nostrils are facing sideways) (new world)

• macaques

• catarrhine (old world monkey) because nostrils are down turn

• lemur

• strepsirrhine

• gibbon

• hominodea

• skilled at brachiation (swinging from tree to tree)

• tend to live in primary groups composed of permanently bonded males and females and their offspring