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Flashcards in primates and humans Deck (46):

general primate classifications

strepsirhines: lemurs and lorises

haplohimes: tarsiers, new work monkeys, old world monkeys, apes


what are apes

hominoids; chimps, gorillas and humans


past classification of primates

promiscians and athiopoids



past classification; lemurs, lorises and tarsiers



past classification; new world, old world monkeys and apes



lemurs and lorsies



tarsiers, new world monkeys, old world monkeys and apes


hands and feed adptations of primates?

1. highly drived hands and feet: for GRASPING

2. flat nails instead of claws

3. sensitive tactile pads with thin ridges on the top of fingers: for sensitivity and better grasping


what do humans lack in hand adaptations

grasping feet


smell adaptation of primates

decreased reliance on smell:

reduction of snouth length and nasal structures in brain regions as smelll less important

tree shrews (big) to bush baby (medium) to tarsier (tiny size)


what smell trait have haplorhines lost

lost rhinarium; the moist skin around the nostrils


increased reliance of vision of PRIMATES adaptations

-forward facing eyes

-enclosed bony orbit (post-orbital bar) for better protectio nof eyes

- binocular and streoscopic vision (trichomatic vision and 3D vision due to overlapping fields of vision)

-trichomatic/dichromatic colour vision


give an example of postorbital change across species

in racoons; open post orbital
in gibbion; is closed
in lemurs; is partially closed


why did primates evolve binocular and stereoscopic vision

for greater depth perception; other mammals dont see distance as intense; rather have wider vision
- its important to manage space and lolomition in compled 3D habitats


what does trichomatic colour vision enable

- in apes, old world monkeys and some new worl monkeys

3 cells for colour process (red, green blue); trichomatic; allows for frugivorous primates to distinish fruit


locomotion patterns in primates

primates have a generalize part-cranial anatomy similar to dolpins that allows for diverse variations of movement such as:
1. quadrupedalism
2. vertical climbing and leaping
3. suspensory and brachiation
4. knuckle walking
5. bipedalism


explain quadrupedalism

- is found in terrestial or arboreal primates such as baboons
-hindlims/forelimps of equal length
-arboreal species have long tails to aid in balance
- lateral position of shoulder blade; restricits movement of shoulder horizontally


explain vertical climbing/leaping

'jumping primates' such as lemurs
-long powerful hind limbs
-long flexible backs
-long fingers for grasping support when landing


explain suspensory/brachiation movement

- in gibbons and spider monkeys
-spidermonkeys have lost thumbs for further grabbing efficency (atteles geoffrey)
-short hindlimbs and long fore limbs
-movile shoulder joints
- long and curled fingers for grasping branches; sometimes tails and hindlimbs used as well
-sholer blade focused on back


knuckle walkign

form of quadrupedalism by great apes like gorilla
-wrist joitns are stabilized
-mainly hindlimbs ar eused
-young individuals use brachiation
-old individuals have to balance body weight by knuckles on ground (hence semi-bipdeal locomotion)


teeth and diet (general) traits of priamtes

-teeth in upper and lower jaw have bilateral symmetry
- vs. in reptiles; teeth are the same
in PRIMATES: HEREDONTS Dentition (different variations of teeth such as incocrs, canines, premolars, molars)


dental classes of primates and their uses

anterior teeth; ingestion

posterior teeth; chewing

incisors; cuting food

canines; tear food (or for SOCIAL vehaviour as display)

premolars and molars; for crushing and grindign


dental formula in mammamals and diferent primates

how many teeth of each class (incisors, canines, premolars, morals)

in ancestral mammals:;
in most strepsirhines, tarsiers and new world monkeys:
in old world monkeys, apes and humans:


carnivore, elephant and primate teeth variations

carnivores: teeth are specialized with high pointed cusps for tearing meat

in elephants; are herbivores so their teeth are broad, and flat surfaces for chewing tough grasses and plants

in primates; are omnivores; generalized diet; low rounded cusps for processing most types of food


insectivory dental adaptations

sharp crests for puncturing the outer skeletons of insects


frugivory dental adaptions

low cusps for crushing soft fruits


folivory dental adaptations

leaft eating; well developed shearing crests for cutting toughy leafy matieral into smaller peices


neutral adaptations of primates

-increased brain size relative to body (elephants have big brains and big bodies, vs primates have medium bodies and big brains)

- larger proporition of brain devoted to conittion, memory and assosiation (not just sensory input)

- social living and complex behavioural patterns


social living adaptation of primates

large/stratified social groups in hierarchial organizaitons

social learning in older individuals; close social bonds

relationship and hierachial awarenss in chimps lemurs and baboons who live in groups


live history adaptation of primates

primates live relatively slow lives compared to animals

hav elonger childhoods for mother and learning period

longer intrevals between birth

fewer off spring; parents invest more time and resources into kis

1 kid every 3-5 years, with a 34 week gestation period and first birth at aroune 14 and 41 year lifespan


impala life history

1 litter every year
27 week gestation period
first birth at 3
12.5 yr lifespan


coyote life history

4-7 litters every year
9 week gestation period
first birth at 3
16 life span


what is primate behaviour influenced by

social structures influenced by reproduction


reproduction assymmetry in primates

assoisated with sociality; females invest more time than males in raising children;

primate mothers are laways primary carefivers of off spring whereas father behaviour is much more variable


female reproductive strategies in priamtes

mammalian reproductive system= significiant initial investment in offspring; energy costin pregnancy and lactation (time and food)

each infant= significant portion of females lifetime fitness

females reproductive success linked with ability to obtain food and support herself/offspring; females distribution selves according to distribution food sources


male reproductive strategies

affected by distribution of females

to maximize fitness need to secure access to females

hence; mating with mulitple females is when resources are distributed in group (polyamarous)

vs. pairbonds/monogramy when females and resources sparesely distributed


sexual dimorphism

male traits have higher POTENTIAL to eolve as large fitness differences assosiated with dominance

dominant males; 100s offspring

non dominant males; no of sprringg

femaes; no strong fitness differences as their sucess measured by ability to produce offspring in a life time


competition for mates in primates

males compete; favours large body size and canine teeth to secure females


types of social system and evolution

monogomous (monomoprhic canines; males evolve more slowly)

polygamous; (domorphic canines; males evolving faster)



all species closel related to humans than chimpanzees or bonobos


major evolutionary novelities of humans (5)

1. habitual pidealism

2. characteristics of dentition

3. significant brain size increas

3. eloboration of matieral culture

5. long developmental period and lifespann


habitual bipdeal locomotion

- humans walk on two feet

ecological fators: moving across forested patches with higher energetic efficeny + finding food + spotting predators

social factors: ability to provide for entire family in tonctedt of evolution of monogamous systems' males to provide for family )carrrying infants, tools and food)


characteirsitcs of human dentition

large canine in male apes but in hominids; reduction of sexual dimoprhism; less male to male competition

different social interactions resulted in a canine reduction


human brain size increase

not in early hominids but later groups
humans have largest brain size to body ratio
chimsp are second; closest relatives

earlies hominids; similar brian size raito to chimps


eloboration of matieral culture

personal otnaments

stone tools (also in chimps; tools to break nuts)

rock, art, music, figurines; smbolic behaviour


long developmental period in humans

humans also have adolesecnee period (which is an evolutionary novelty)

general LONGER developmental period

humans born underdevlped (attricial)

males; are more involved in patenral care; stable bonds