ANT 200 Midterm #1

lecture 2

2

Tinbergen’s 4 questions

• mechanism (causation): how trait works

• function (adaptive): why is behavior adaptive

• ontogeny (development): how has this behavior developed

• phylogeny (evolution): why did this trait evolve

tinbergen’s questions with capuchin monkeys

• mechanism: seeing a nut activates feeding motivation in head, chooses a rock based on nut density

• function: allows higher energy foods to be consumed

• ontogeny: young C develop through maturation, practice, and watching

• phylogeny: has deep roots in capuchins, exists in other populations

capuchins populations

sapajus: long term documentation of tool use

cebus: recently started using stone tools

behavior

the way an organism acts in response to an internal or external stimuli

behaviorism (american)

idea that everything is learned and can turn any child into anything

regardless of species, all organisms start as blank slate, all interactions and behavior are learned behavior

behaviorism laws

equipotentiality: any 2 stimuli can be associated regardless of nature through experience

animal behavior is respondent or operant

• respondent: involuntary response to stimuli

• operant: associate a voluntary response to reward/consequence

worked w rats in labs

operant vs classical/respondent conditioning

operant: from Skinner

• reinforcement/punishment, voluntary actions are evoked

classical/respondent: from Pavlov

• neutral stimulus w unconditioned stimulus

umwelt

perceptual world in which each organism exists and acts in

ethology/ethologists (tinbergen) (european)

‘watched and wondered’

worked w birds, insects, fish

emphasized:

• naturalistic observation

• comparisons across species

• function and evolutionary history of behavior

karl von frisch

studied bees and found that they have color vision and can communicate through dancing

konrad lorenz

studied imprinting w ducks

niko tinbergen

studied instinct within baby herring gulls that peck at red in mother’s jaw

fixed action pattern: instinctive behavior that are highly stereotyped, instinctive behavior like parenting/mating

charles henry turner

experimented w bees, ants, wasps to demonstrate learning and memory in insects

studied bee color and pattern discrimination, conditioning in insects

he was black and his efforts were ignored for white counterparts

margaret morse nice

studied territory, courtship, song, reproduction, and life of sparrows

ignored for being a woman

zing-yang kuo

studied development of behavior and how experience shapes actions, diff btw innate and learned behavior on cats & rats

ignored for being chinese

robert yerkes & Lorenz

eugenics and nazi linked from taking info from animal experiments to humans

evolution

change in genetic material of a population over time

1. NS

2. genetic drift

3. mutation

4. gene flow

natural selection

individuals w traits that are better adapted to their environment will by more likely to survive and reproduce

1. variation

2. heritable variation

3. random breeding

lamarck

theory of use and disuse

mechanisms for variation

mutation

recombination/mating

gene flow

directional selection (NS)

selection favoring one phenotype, either/one side of graph

stabilizing selection (NS)

selection favoring intermediate phenotype, middle of graph

disruptive selection (NS)

selection favoring extreme phenotypes, both sides of graph

genetic drift

bottleneck effect

founder effect

lecture 4

4

levels

kingdom → phylum → class → order

primitive traits

traits inherited from a distant ancestor

derived traits

shared traits due to a recent common ancestor that sets taxa apart

distinguishing traits

pentadactylism: 5 digits on hands and feet

elongation of fingers and toes

opposable thumb

nails instead of claws

stereoscopic vision: forward facing eyes (better depth perception and predation ability)

color vision (mammals are dichromats, primates are trichromats)

snout reduction → large brain

lengthening of life history traits

phylogeny

evolutionary history of a group

• taxon/taxa: grouping more closely related to another at the exclusion of others

• branch: line representing an evolutionary lineage

• node: point where branches

order → suborder → blah picture memorize

strepsirhines splits into ?

splits into lemuroidea & lorisoidea

• long, wet snouts

• eyes reflect light

• noturnal & solitary

• small brains & body

• fast life history

lemuroidea

• small bodied

• diurnal

• dependent on scent

• social

• female dominated

lorisoidea

• small

• omnivore

• nocturnal

• solitary

• arboreal

• venomous

catarrhines

splits cercopithecoidea & hominoidea

hominoidea splits into hylobatidae & hominidae (apes & people)

primates

splits into strepsirhine & haplorhine

strepsirhine (lemurs and lorises)

• long, wet nose

• nocturnal

• eyes reflect light

• small body & brain

• fast life history

haplorhine (monkeys and apes)

• short snouts

• dry nose

• diurnal

• large body & brain

• slow life history

haplorhine splits into?

splits into

• tarsoidea: small, carnivorous, nocturnal, arboreal, solitary

• ceboidea: new world monkey, prehensile tail, arboreal, flat nose

  • ex: capuchins

• catarrhines: cercopithecoidea & hominoidea

  • old world monkeys: hooked noses, terrestrial, no tail, social

cercopithecoidea & hominoidea —> catarhines

cercopithecoidea: old world monkeys, small, narrow chested, fixed shoulders, quadrupedal, above branch locomotion

hominoidea: no tail, large body and chest, flexible shoulder, brachiator below branch, big brains

hominoidea

splits into

• hylobatidae: gibbon & siamang

• hominidae: pongo(orangutans), gorilla, pan(bonobos & chimpanzee), homos → tool use, culture, communication

chimpanzee

large bodied

omnivores

females leave social group

hunt, territorial

bonobos

smaller, slender

herbivore

female dominant

less aggressive than chimps

GAYYYYYY

lecture 5

5

Understand and describe the key patterns in human evolution

• a. Articulate the key differences between current and past understanding of these patterns

2. Describe the adaptive suites of early hominins, Australopithecus, and Paranthropus

3. Understand the differences between taxic and morphological diversity (or, to use some jargon, diversity and disparity)

4. Discuss the tension between diversity and disparity, and the role that new discoveries play in resolving this tension

early hominins

knuckle walking, small brains & bodies

austrolopiths (group of early hominids)

ape like:

• small brain, prognathic (outward jaw), long arms

human like:

• thick enamel, loss of Cp3 honing complex (tooth), forward foramen magnum (where brain & spinal cord connect), round pelvis

had a diamond face shape, dimorphic canines, large postcanine dentition, sexual dimorphism, wide stance

paranthropus (group of hominids)

sagittal crest, dished face, flat face, large temporal fossae, strong postorbital constriction, large back teeth (postcanine) & tiny front dentition

lots of chewing

macroevolution

origin, maintenance, and loss of bioD above species level

how new brains form, expand, and disappear

taxic/classic diversity

how many species are there

morphological diversity / disparity

how different are these species

diversity & disparity uncoupled

tension btw diversity & disparity

we use morphology to identify species

thru history more diversity than disparity exists but some new discoveries increase disparity (increases in diversity have outpaced increases in disparity)

• morphology must demonstrate a difference in niche

Lecture 6

6

some animals have diff levels of disparity vs diversity

malagasy mouse lemurs: low disparity, high diversity

australopithecus: med disparity, high diversity (both have increased since the 90s)

genus homo

• bipedal, opposable thumb

• smart with smooth skull

• small teeth, large body

• tool user, human feet

remarkably anatomically homogenous

history of genus → 3 stages

early homo: mixture of traits of homo habilis & rudolfensis

homo erectus: spread from africa to eurasia, tools, fire, big brain

late homo: large brain & body, complex stone tool use, symbolism, extinctions

adaptive introgression

introgression from denisovan to homo sapiens

• could live in higher altitude, low O2 conditions

cognition in homosapiens vs neaderthals

homo:

• larger cerebellar hemispheres→ attention, cognitive flexibility, language, memory

• developed FOXP2: mutations in gene develop speech apraxia

neanderthals:

• larger occipital regions, better vision

• also have FOXP2

Lecture 7

7

why primate brains change

• selective pressure to increase brain size (cranial capacity): volume of inside of the skull

• diff in brain structure

brain size

• absolute brain size: measurement of animal’s brain unit

• relative brain size: brain size relative to overall brain size, directly related to cognition

allometry

study of how one part of organism grows in relation to whole other organism/another part

departures for expected growth patterns from allometry shows evidence a trait is under selection

• in mammals brain size increases at slower rate than (- allometry)

encephalization quotients

how much brain size of a species differs from the expected brain size

>1 → larger brain than expected

<1 → smaller than expected

• primates have largest EQs and greatest increase in EQ among mammals

triune brain model: divides human brain into 3 evolutionary layers

reptilian brain: brainstem & cerebellum → instinctive survival (HR, breathing)

paleomammalian brain: limbic system → emotion, memories, attachment

neomammalian brain: neocortex → reasoning, language, planning

all vertebrates have same general brain layout

hindbrain: basic life support, movement, coordination

• medulla, pons, cerebellum

midbrain: orienting, attention, movement

• visual and auditory info, responses, pain regulation

forebrain:

• olfactory, thalamus, basal ganglia

cerebral neocortex: thin layer covering cerebral hemispheres→ learning, memory, decision-making

evolution in primate brain

reduction in olfactory bulb

cortical expansion and folding

expansion of prefrontal cortex

increased connectivity→ integration across brain regions

occipital lobe

visual perception

parietal lobe

tactile perception, understanding, movement

temporal lobe

hearing, memory, identity

frontal lobe

cognitive function, concentration, problem-solving, planning, learning, abstract thought

brains are 2% of body weight but

require 20% of energy

are adaptive

ecological intelligence & social intelligence hypothesis

ecological: large brains evolved from necessity to locate & extract food, advance cognitive traits

• frugivores have bigger brains than folivores, chimps eat fruits/nuts, bonobos eat herbs

social: large brains evolved as response to living in big/complex groups

• kin recognition, relationships/friendships, empathy, social learning

both are true, diff processes shape diff cognitive domains

why did primate brains change?

expansive tissue & cultural intelligence hypothesis

expansive tissue: large brains require more energy → cooking, better diets, food sharing

cultural intelligence: social learning, behavioral innovation, tool use helped evolve brain → understanding space, causality, communication

all correct

why did human brain change?

lecture 8

8

Nervous system structure and function: • 2 systems • Neurons • Nonneuronal cells • Brain structure and function • 4 subsections of the brain • Cortical fields

How does the brain perceive stimuli? • in this lecture, visual stimuli? • How does phylogeny shape the brain? • How does ontogeny shape the brain? • in this lecture, cortical visual processing

nervous system

peripheral nervous system

• nerves

central nervous system

• brain & spine

vision

photoreceptor → bipolar cell→ ganglion cell → (optic nerve) → lateral geniculate nucleus → primary visual cortex

neuron

fundamental unit of brain, cell, transmits electrical(AP)/chemical(NT) signals

myelin sheath: insulation

nodes of ranvier: gaps in myelin

info in AP is encoded in frequency not amplitude

neuron types

75% are pyramidal neurons

bipolar, unpolar, multipolar neurons

nonneuronal cells

astrocytes: satellite cell in PNS

oligodendrocytes: schwann in PNS → creates myelin

microglia

ependymal cells

4 components of brain anatomy

white matter: grey cell bodies, white axons

limbic systems: thalamus, hippocampus, hypothalamus, amygdala

cerebral cortex

brain stem & cerebellum

hindbrain

brainstem: medulla & pons & midbrain

• basic life support

cerebellum

• movement and coordination

limbic system (PHATH)

pituitary: hormone releasing

hippocampus: memory

amygdala: emotion

thalamus: sensory & motor system

hypothalamus: feeding, fleeing, fighting, reproduction

white matter

white because of myelin

• neural communication

• learning/skills

• cognitive function

• brain development

cerebral cortex

occipital lobe

temporal lobe

frontal lobe

parietal lobe