ANTH 225 Exam 2

________ are our closest living relatives

Non-human primates

shared derived traits

traits multiple groups have in common

comparative method

links anatomy with behavior and ecology

early primate behavioral studies

unsystematic; studied animals in captivity

1st mammals in _________ era

mesozoic

adaptive radiation

rapid expansion and diversification of lofe forms into new ecological niches

primate shared derived traits with all mammals….

makes them primitive for primates; each primate group has own set of shared derived traits

heritage of mammals…

possess modified sweat glands that produce milk

heritage of eutherian mammals…

placenta

placenta

organ that allows exchange of gases, nutrients, & waste elimination during gestation

shared derived trait with mammals

increased brain size; enlarged cerebral cortex

K-selected

emphasis on quality offspring & specialization

primate shared derived traits

opposable thumbs & milk producing

ape shared derived traits

opposable thumbs & lack of tail

homologous primate shared derived traits (8)

grasping hands & feet, binocular vision, reduced reliance on olfaction, generalized dentition, reduced dentition, relatively large brains, relatively slow life history

grasping hands & feet

enhanced sense of touch (nails instead of claws)

binocular vision

forward orbits (orbital convergence), more reliance on vision

reduced reliance on olfaction

loss of rhinarium in MOST primate groups

reduced snout

less prognathic than other mammalia

prognathic

pushing out snout

rhinarium

wet nose

generalized dentition

aren’t specific to what we eat; incisors, molar, canines, premolars; 4 quadrants of the mouth

primate dentition

bilophodont or Y-5 molars

reduced dentition

lost teeth through our evolutionary history (premolars, incisors, etc)

relatively slow life history

longer gestation, maturation period, age to reproduction & life span

anthropoids incude:

(greater apes, small apes)&(cercopithecines, colobines)

haplorrhines include:

anthropoids, platyrrhines and tarsiformers

tarsiformers include:

tarsiers

same common ancestor as haplorrhines

sterpsirrhines

strepsirrhines

least closely related to humans based on shared derived & genes; lemurs, lorises & galagos; rhinarium; most prognathic; reliance on night vision; grooming claw and dental comb

haplorrhines

greater reliance on right, post orbital bar/closure; no tapetum lucidum; decreased reliance on smell (dry nosed/reduced snout); larger brain; no dental comb

tarsiiforms

SE Asia; only fully carnivorous primate

Anthropoids

all monkeys, apes & humans

platyrrhines

new world monkeys, C + S america; diurnal, arboreal, prehensile tails, 2.1.3.3 dental formula

marmosets & tamarins

smallest group, common in zoos, inly primates to regularly have twins, only primates with more than 2 nipples

largest platyrrhine

howler monkeys

capuchin monkeys

largest brains relative to body size after great apes

catarrhines

circopithecoids & hominoids, 2.1.2.3

cercopithecoidea

paraphyletic, old world monkeys, subfamilies (colobines & cercopithecines), bilophodont molars

circopithecoid species’

macaques, baboons&mandrills, colobus monkeys, old nosed monkeys

hominoidea

lesser & greater apes, relatively long arm and brachiation; no tail, Y-5 molars, enlarged brain

hylobatidae

lesser apes (gibbons & siamongs), extreme brachiation, SE asia

hominidae

ponginae and gorillinae

ponginae

orangutans (Pongo), almost completely arboreal, frugivorous, bornea & sumatra

gorillinae

gorillas (gorilla); central africa (forested); knuckle walkers, herbivorous

homininae

panini and hominini

panini (chimps)

chimpanzees (pan troglodytes); equatorial africa; knuckle-walking & brachiation; omnivorous; large communities

panini (bonobos)

pan paniscus; found only in DRC south of congo river; omnivorous; matrilineal

hominini

u & all fossil hominins; mostly terrestrial; complex language; distinctly amnivorous; rely on technology

primate closest living relatives

colugos & tree shrews

shared traits with primates from closest living relatives

large eyes, mobile hands & feet

different traits with primates from closest living relatives

claws instead of nails, lack binocular vision, no opposable thumbs/toes

plesiadapiformes

skeletons primate-like but teeth specialized, no postorbital bar

euprimates-eocene

adapoids & omomyoids by early eocene, primitive dentition, adaptive radiation in the early eocene, reduced by end of eocene, extinct in NA by 35 Ma

euprimates-eocene shared derived primate features

forward facing eyes, greater encephalization, post-orbital bar, nails instead of claws, opposable big toe

euprimate: adapoids traits

reduced nasal area, post-orbtial bar, strong leaping adaptations, grasping hands&feel with nails, some have dental combs

Darwinius masillae

rtansition between strepsirrhines & haplorrhines

Euprimate: omomyoids

tarsier-like, dental formula, large orbits, small snouts, mostly insectivorous

earliest haplorrhines

larger body, larger brain, post-orbital closure, fused mandible, bilophodont molars

oligocene

Egypt, more primates in younger deposits

happlorhines at oligocene site

parapithecids, propliopithecids, platyrrhines

propliopithecids

aegyptopithecus, arboreal quadruped, 2.1.2.3, significant sexual dimorphism

platyrrhines

platyrrhine dentition, some terrestrial morphology, 1st from Egypt then S America

old world monkeys

derived traits of both extant OWM subfamilies

oldest “modern” monkeys

victoriapithecidae

how did primates end up in the americas?

hypothesis 1

evolved from primates already there BUT primates gone from americas ~35 Ma

how did primates end up in the americas?

hypothesis 2

descended from Egyptian platyrrhines BUT no platyrrhines in americas pre-28 Ma

how did species get to the americas

mangrove island rafts

cercopithecoids (early catarrhines)

victoriapitheus; E. africa, oldest OWM, Bilophodont molars

Earliest hominoids

mostly from E. africa, first Y-5 molars & thick enamel, vary in size & locomotor adaptations

proconsuloids (earliest hominoids)

ape-like, ekembo, 22-110 lbs, skeleton monkey-like, probably lacked a tail, Y-5 dental pattern

afropithecus (earliest hominoids)

1st ape-like primate outside Africa, quadrupedal arboreal lifestyle

miocene hominoids (asia)

sivopithecus and yuanmoupithecus

sivopithecus

india, only miocene ape linked to modern ape, likely related to orangutan

yuanmoupithecus

possible gibbon/saimang ancestor, China

miocene hominoids (Eurasia)

Gigantopithecus

Gigantopithecus

china, largest ape ever, lower jaws & isolated teeth, overlap with early humans?

miocene hominoids (africa)

evolve into LCA of apes & human, modern african apes descended from european apes

plio-pleistocene

“modern” cercopithecoids, baboons & macaques by late miocene, overlap in size, diet & environment w/ early humans, ecological referent

plio-pleistocene link to human

modern chimp, gorilla, & human lineages not established until late miocene

field studies

studying free-ranging primates in natural habitats using evolutionary perspective

field studies important because…

minimizes human interference & “unnatural behaviors”, helps to explain ecology, behavioral ecology, & human-primate cultural relationships

ecology

inter-ralationships of animals, plants & physical environment

behavioral ecology

behaviors evolved through natural selection within the context of particular environments

primate locomotor modes (5)

(1) arboreal quadruped (2)terrestrial quadruped (knuckle-walking) (3)vertical clinger & leaper (4)suspensory/brachiation (5)orthograde bipedalism

how can functional morphology be applied to the fossil record?

comparative morphology, qualitative & quantitative analyses

Intermembral Index (IMI)

(arm length/leg length) * 100

IMI <100

legs longer than arms, vertical clinging/leaping, bipedalism

IMI >100

legs shorter than arms, suspension/brachiation

IMI =100 ±10ish

arm & leg similar length, arboreal or terrestrial quadrapedalism

primate social disadvantages

fod competition, predator visibility, mate competition, social tension/violence

primate social advantages

access to food, predator defense, mate access, assistance in care of young

mating system

who is mating with who

social system

composition of the group

mating & social systems ____ correlate, but some _______ systems can vary in _______ system depending on species and vice versa!

Do; social; mating

philopatry

remaining in one’s natal group upon reaching adulthood

sexual selection

type of natural selection, result of competition for mates, leads to sexual dimorphism

alloparenting

care provided by someone other than parents

social systems

basic social unit (adult female & offspring), alloparenting

polygyny (1M/1<F)

male has multiple mates, female philopatric