ANTH 168 CH5-8

Primates

“highest”, “of the first rank, chief, principal” order (Linnaeus)

Clades

group of organisms based on relatedness

Homology

traits shared between taxa, inherited from common ancestors

Analogy

similar traits, but not from a common ancestor

Grade

overall physical similarity

Monophyletic Clade

ancestor and all descendents

Paraphyletic clade

ancestor and some descendants

Polyphyletic clade

group of descendants and ancestors, but not common ancestors

Ancestral trait

a trait that arose prior to the most recent common ancestor

Derived trait

a trait inherited from a recent common ancestor

Generalized traits

adaptable with a multitude of purposes, like thumbs

Specialized traits

modified for a specific purpose, like hooves

The Primate Pattern

group of mammals with visual specialization, grasping hands & feet, large brains, and long-life histories

Eye sockets specific to primates

Post-orbital plate closure and bar — Protects the side of eyes from muscles used for chewing & general protection

trichromatic vision

a modern primate trait, while ancestral trait is dichromatic

Arboreal vs. terrestrial life history

tree life vs ground life, a good distinction in primate history

Frugivores

insect leaves, seed diet. characterized by bunodont/4-cusp molars for cutting through fruit skin (DENTAL FORMULA 2:1:2:3)

Insectivores

insects…! bilophodont molars, for smaller primates

Folivores

complex stomachs for eating leaves, larger primates who spend most of their time eating. broad molars and shearing crests for leaf ripping

Cathemeral

active both day and night

Nocturnal

active at night

Diurnal

active during the day

Locomotion

how primates move around

Brachiation

swinging from branch to branch

Strepsirrhini

a sub-order of the most ancestral primates

traits: wet noses (rhinariums), great sense of smell, tapetum lucidum

main groups: lemurs, lorises, pottos, galagos (af/as)

grooming claws and tooth combs

Rhinariums

wet noses which are present in strepsirrhinis

tapetum lucidum

reflective layer on back of eye for night vision

Lemurs

strepsirrhini that have a diverse diet, located in madagascar

Lorises, Pottos, Galagos

share environment with other primates, eats primarily fruit and insects

Haplorrhini

sub-order characterized by literally the opposite of strepshirrini, alos have postorbital plate and better vision

Tarsiiformes

infraorder from haplorrhinis, nocturnal and faunivorous (only one), enormous eyes and elongated tarsal bone. loves to cling and leap

Platyrrhini

infraorder from haplorrhinis,flat noses, dental formula (2:1:3:3), prehensile tail, ex: spider monkeys

located in central/south america and the only nonhuman primate there

catarrhini

infraorder from haplorrhini, tear-drop shaped nostrils, 2:1:2:3 dental formula, diurnal and great vision as well

Cercopithecoidea

super family of catarrhini, still quadrupedal, bilophodont molars, have calluses on pelvis for sitting on rough rocks

Hominoidea

superfamily of catarrhini, consists of apes and humans, Y-5 cusp pattern on molars (ancestral), brachiated, slow reproduction potential

Hylobatidea

Gibbons and siamangs, live in pairs with little sexual dimorphism

Pongo/Orangutans

Reproduce extremely slowly, highly sexual dimorphic

Gorillas

Highly sexually dimorphic, quadrupedal, Have large sagittal crests like pongos

Bonobo

highly matriarchal, use sexual interaction to reduce conflict in troops

Chimpanzee

highly patriarchal and aggressive, Largely frugivorous diets, knuckle-walking. Cooperative hunting… our closest ancestors!

Modern Humans

• No tail, upper body adaptation for brachiation

• Y-5 cusp pattern on molars, generalized diets

• Cooperative hunting

Sagittal Crest

crest on forehead to hold muscles for chewing

Primatology

branch of science that studies primates

The Leaky ‘Trimates’

Jane Goodall studied chimpanzees in Tanzania

Birute Galdikas studied orangutans in Borneo

Dian Fossey studied gorillas in Rwanda (controversial)

Ecology

relationship between organism and their respective environment

Food factors

Abundance, Distribution, Quality

Community Ecology

relationships and interactions between different organisms that occupy the same habitat

Conspecific

same species

Heterospecific

different species

Uniform distribution

food is spread out evenly

Clumped distribution

food found in patches

Random distribution

neither uniform or clumped, just… random!

How do primates avoid competition?

They live together in different ecological niches

Direct Competition

physical interactions over resources

Indirect Competition

arriving at food source quicker before others can reach it

Predator-Prey

Certain primates engage in predation (and are naturally prey from other species)

Mutualistic

different species working together

Polyspecific associations

A type of mutualistic interaction where a relationship between 2 or more species is maintained by behavorial changes by at least one of the species

Parasitic-Host

benefit off of the host while the host is affected negatively, happens commonly between primates that groom. mandrills and chimpanzees have defensive mechanisms against these

Human-Primate

in some areas, primates are hunted for meat, trophies, or pets (infant) by humans

Ecotourism

focuses on nature-based attractions that are economically and ecologically sustainable (a type of human-primate interaction that is positive)

Why do primates hang in groups?

 enhanced feeding competition, predator avoidance, reproductive success

Solitary (primate social system)

primates do not live or travel together, sexual dimorphism

Polygyny

males who mate with multiple females

Single-male, Single-female

2-5 individuals per group, pair bonding, monogamous, sexually monomorphic

Examples of single-male, single-female primates

gibbons and owl monkeys

Single-male, Multi-female (Polygny)

5-50 individuals per group, males disperse while females are philopatric, the resident male is aggressive towards other males. If a new male takes over, he will infanticide to increase his own offspring’s survival chances

Examples of polygyny primates

gorillas, patas monkeys, golden snub-nosed monkeys

Multi-male, Multi-female (Polygamy)

10-500 individuals per group, polygamous mating system, less extreme dimorphism, males still compete with each other

examples of polygamy primates

vervet monkeys, ring-tailed lemurs, white-face capuchins, and black capped squirrel monkeys

Fission-Fusion

10-12 individuals per group, size and composition fluctuates based on resource availability, males are philopatric while females disperse

examples of fission-fusion primates

geoffrey’s spider monkey and chimpanzees

Multi-male, Single-female (Polyandry)

2+ males w/ 1 female (and offspring), polyandry, cooperative breeding (multiple males invest in the offspring)

examples of polyandry primates

marmosets and tamarins

Parental Investment

time/energy parent invests to enhance offspring survival

Sexual Selection

selection for traits that maximize mating success

Intrasexual selection

enhance traits to compete with same sex

Intersexual selection

enhanced traits to attract the other sex

Evolutionary trade-off

basically giving up one thing for another, happens in sexual strategies as well

Vocal communication

loud calls, contact calls, screeching

Visual communication

facial expressions, piloerection, sexual swelling, facial coloration (bald uakaris)

Olfactory communication

scent glands, urine washing (warn strangers)

Tactile communication

grooming (reinforce social bonds, repair relationships, cement alliances)

Culture

transmission of behavior via social learning

Tradition

pattern of behavior shared by individuals in a social group that persists over time

Traditions within Chimpanzees

prey preference, specific hunting techniques, tool-use, social behavior

Traditions within Macaques

washing potatoes, spanning 30 years, hot springs

Importance of fossils

Demonstrate change in traits over time, adaptation, as well as derived traits, most importantly our own hominid lineage

Megalithic Dolmen structures

showed that the Earth was not as young as religious texts would say

WEET

western eastern evolutionary thought, which relies heavily on religion to explain the history of the world

Geological Time

refers to the Earth in distinct phases, each with defining features

Eon

billions of years — Hadean, Archean, Proterozoic, and Phanerozoic

Era

hundreds of millions of years — Phenerozoic eon is split into three eras: Paleozoic, Mesozoic, Cenozoic

Period

tens of millions of years — Mesozoic era is split into three periods: Triassic, Jurassic, and Cretaceous

Epoch

several million years — Cenozoic Era’s Quaternary period is divided into the Pleistocene and Holocene epochs

Current Geological Time…?

Phanerozoic Cenozoic Quaternary Holocene/Anthropocene

Taphonomy

what happens to an organism after burial/death, affected by environment, ecosystem, context, and change

Fossilation

the preservation of an organism against natural decay processes… bones and teeth preserve better

Lithification

loose sediment turns in rock

Permineralization

cast of the organic tissue is created through sediment-rich water infiltration, keeping the original shape