120 ANP Introduction to Physical Anthropology
Macroevolution, I.
Review Part 2 Lecture #26
ANP 120 Lecture #14
What you should know:
what is the biological species concept and what are the problems applying it? what are anagenesis and cladogenesis? what is allopatric speciation and how does it work? how do traits change in phyletic gradualism and punctuated equilibrium? why do species go extinct and what is the role of extinction in evolution?
Biological evolution
genetic change through time
microevolution
short-term change population level
macroevolution
long-term change species level
What is a species?
Biological Species Concept
a group of interbreeding natural populations that are reproductively isolated from other such groups
What is a species?
Biological Species Concept
a group of interbreeding natural populations that are reproductively isolated from other such groups
gene flow
no gene flow
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Problems with applying BSC
allopatric populations fossil record and extinct species
agile gibbons
Problems with applying BSC
allopatric populations fossil record and extinct species
??? interbreeding ???
Modes of species origin
Anagenesis (phyletic transformation)
single species undergoes gradual change and transforms over time
Modes of species origin
Cladogenesis
branching evolution involving the splitting of a species
Species A Species B
Form A
Form B
Form C
TIME
Species C
NO increase in species number
TIME
Increase in species number
Allopatric speciation
Interbreeding populations (gene flow)
Isolated populations may develop differently (natural selection, mutation, genetic drift, founder effect)
Phyletic gradualism
change is constant & slow
Barrier prevents interbreeding (no gene flow)
Two new species (do not interbreed, even if they meet)
Value of a trait
Time
2
Punctuated equilibrium
Adaptive Radiation
periods of little and rapid change
Value of a trait
P2 P1 E1
Time
E3
The formation of many new species following the availability of new environments or the development of new adaptations
E2
Hawaiian honeycreeper finches
Extinction
due to
rapid environmental change changes in food availability competition from other species
Role of extinction
Present day Present day
?
Increasing diversity Decimation followed by diversification of surviving species
What you should know:
what is taxonomy? what is a phylogeny and what techniques are used to study it? what are homology and analogy and how do they come about in divergent evolution and homoplasy?
Macroevolution, II.
ANP 120 Lecture #15
how are traits characterized and how are they used in classification? what is the difference between cladistic and traditional evolutionary classification?
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Taxonomy
the science of classifying or naming organisms in a hierarchical manner
Phenetic classification
based on physical similarities or differences
trucks
SUVs
Pan paniscus
Pan troglodytes
Phylogeny
reconstruction of an evolutionary branching sequence ancestor-descendent
How to study phylogeny
molecular techniques
DNA hybridization DNA sequencing
phylogenetic classification
cladistic traditional evolutionary
immunological methods
Morphological techniques
describe similarities and differences of morphological traits
cat hair mammary glands vertebral column yes yes yes dog yes yes yes fish no no yes mosquito no no no
Characterizing similarities
homology
similar by common ancestor
analogy
similar due to common function (not ancestor)
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Divergent evolution
species become dissimilar (e.g., different environments) clades based on homologies
clade: members of an evolutionary cluster with a recent common ancestor (not shared by others)
bony ring bony socket
Homoplasy
species become similar (similar environments) grades based on analogies
grade: members of a cluster sharing functionally similar features (no recent common ancestor)
New World monkeys
similar niche similar niche
Apes
ancestor
ancestor
ancestor
Characters of traits
primitive
inherited from early ancestor; widely shared
Cladistic classification
shared derived
inherited from recent ancestor; shared by few unique for a species
based on derived traits (traits w/ equal weights)
unique derived
Traditional evolutionary classification
based on derived traits (weighted traits)
What is a primate?
ANP 120 Lecture #16
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What you should know:
what is the taxonomic position of primates? why are primates hard to classify relative to other mammals? what are the traits that are used to describe primates? what is the trait defining primates (unique to primates)? what are the 4 hypotheses proposed to explain primate adaptations?
Primate classification
KINGDOM PHYLUM SUBPHYLUM CLASS ORDER Animalia Chordata Vertebrata Mammalia Primates
Primates
gorilla mouse lemur
Summary of primate characteristics
hard to define
primitive traits traits shared w/ other orders diverse
hands and feet
grasping; tactile pads; nails instead of claws (big toe) eyes forward; stereoscopic vision; complex retina; bony ring/ socket reduction snout and olfactory apparatus
improved vision
reduced sense of smell dental characteristics
heterodont; reduced numbers; simple molars large and complex brain (visual, motion, cognition) lengthened maturation; long life span; low reproductive rate
described by
combination of traits 1 defining trait
general
internal ear structure
auditory bulla from petrosal bone
Internal ear structure
auditory bulla made from petrosal bone
Proposed explanations - 1
arboreal theory
GE Smith, F Wood Jones, WE LeGros Clark
movements in the trees grasping hands & feet, vision, brain
temporal bone petrosal bone
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Proposed explanations - 2
visual predation theory
M Cartmill
capturing prey (night-time) vision, grasping hands & feet
Proposed explanations - 3
terminal branch feeding theory
RW Sussman
feeding on fruit & nectar grasping hands & feet
Proposed explanations - 4
visual predation & terminal branch feeding theory
DT Rasmussen
combining 2 & 3
Overview of Living Primates, I.
ANP 120 Lecture #17
What you should know:
what is the cladistic taxonomy of primates (to the superfamily)? what is the difference compared to the traditional classification? what are the morphological differences of strepsirhine and haplorhine primates? where do lemurs, loris, galagos and tarsiers live and what are their basic lifestyles?
Primate taxonomy (cladistic)
Order Suborder Infraorder Lemuriformes Strepsirhini
(lemurs)
Superfamily
Lemuroidea Lorioidea
Loriformes
(loris & galagos)
Primates
Tarsiiformes
(tarsiers)
Tarsioidea
Haplorhini
Platyrrhini
(New World monkeys)
Ceboidea Cercopithecoidea
Catarrhini
(Old World monkeys)
Hominoidea
(apes and humans)
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Primate taxonomy (traditional)
Order Suborder Infraorder Lemuriformes
(lemurs)
Primate taxonomy (cladistic)
Superfamily Order Suborder Infraorder Lemuriformes Strepsirhini Lorioidea Tarsioidea Primates
(lemurs)
Superfamily
Lemuroidea
Lemuroidea Lorioidea
Prosimii
Loriformes
(loris & galagos)
Loriformes
(loris & galagos)
Tarsiiformes
(tarsiers)
Tarsiiformes
(tarsiers)
Primates Platyrrhini
(New World monkeys)
Tarsioidea
Ceboidea Cercopithecoidea
Haplorhini
Platyrrhini
(New World monkeys)
Ceboidea Cercopithecoidea
Anthropoidea Catarrhini
(Old World monkeys)
Catarrhini
(Old World monkeys)
Hominoidea
(apes and humans)
Hominoidea
(apes and humans)
Suborder differences
Strepsirhines
primitive snout w/ wet nose "twisted nostrils" dental tooth comb bony ring (eye) un-fused frontal bone lacrimal bone outside orbit tapetum lucidum no retinal fovea
Primate taxonomy (cladistic)
Haplorhines
reduced snout w/ dry nose "simple nostrils" no dental tooth comb bony socket (eye) fused frontal bone lacrimal bone inside orbit no tapetum lucidum retinal fovea
Order Suborder Infraorder Lemuriformes Strepsirhini
(lemurs)
Superfamily
Lemuroidea Lorioidea
Loriformes
(loris & galagos)
Primates Tarsiiformes
(tarsiers)
Tarsioidea
Haplorhini
Platyrrhini
(New World monkeys)
Ceboidea Cercopithecoidea
Catarrhini
(Old World monkeys)
Hominoidea
(apes and humans)
Places and lifestyles
Lemuriformes
(lemurs) Geo.-Area Body size Activity Diet Grouping Madagascar small-medium nocturnal, diurnal cathemeral insects, gum, fruits, leaves solitary, pairs, small groups (galagos / loris) Africa / Africa-Asia small nocturnal insects, gum, fruits solitary
Loriformes
Tarsiiformes
(tarsiers) SE Asia small nocturnal animal matter variable
Overview of Living Primates, II.
ANP 120 Lecture #18
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What you should know:
what are the morphological differences of platyrrhine and catarrhine primates? what are special traits of callitrichines (dental formula) and atelidae (tail)? what are the morphological differences of colobine & cercopithecine primates? where do New & Old World monkeys live and what are their basic lifestyles?
Primate taxonomy (cladistic)
Order Suborder Infraorder Lemuriformes Strepsirhini
(lemurs)
Superfamily
Lemuroidea Lorioidea
Loriformes
(loris & galagos)
Primates
Tarsiiformes
(tarsiers)
Tarsioidea
Haplorhini
Platyrrhini
(New World monkeys)
Ceboidea Cercopithecoidea
Catarrhini
(Old World monkeys)
Hominoidea
(apes and humans)
Infraorder differences
Platyrrhines
nostrils round, widely spaced, facing sideward dental formula 2 1 3 3 (but callitrichines) ectotympanic bone ring, no bony ear tube skull zygomatic-parietal contact
New World monkeys
nostrils narrow, facing forwarddownward dental formula 2123 ectotympanic bone bony ear tube skull frontal-sphenoid contact
Catarrhines
living
fossil
Characteristics Callitrichinae
Atelidae
prehensile (grasping) tail
ventral surface of an Atelidae tail
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Primate taxonomy (cladistic)
Order Suborder Infraorder Lemuriformes Strepsirhini
(lemurs)
Old World monkeys
Superfamily
Lemuroidea Lorioidea
Loriformes
(loris & galagos)
Primates Tarsiiformes
(tarsiers)
Tarsioidea
Haplorhini
Platyrrhini
(New World monkeys)
Ceboidea Cercopithecoidea
Catarrhini
(Old World monkeys)
Hominoidea
(apes and humans)
Subfamily differences
Colobines
no cheek pouches complex stomach molars w/ high cusps narrow incisors broad interorbital region reduced thumb
Places and lifestyles
cheek pouches simple stomach molars w/ low cusps broad incisors narrow interorbital region normal thumb (New World m.) Geo.-Area Size Activity Diet Grouping Central & South America small-medium diurnal (Aotus: nocturnal) insects, fruits, (gum, leaves) pairs, groups
Cercopithecines
Platyrrhini
Cercopithecines
(cheek pouch m.) Africa & Asia (small)-medium diurnal fruits, omnivore (insects) larger groups
Colobines
(leaf m.) Africa & Asia (small)-medium diurnal leaves smaller groups
What you should know: The Apes Overview of Living Primates, III.
what are the morphological differences of cercopithecoidea and hominoidea? what is the taxonomy of the hominoidea? who are the lesser and great apes and where do apes live? what are the lifestyles of the different apes ?
ANP 120 Lecture #19
which apes are using tools and which species is the most avid tool user?
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Primate taxonomy (cladistic)
Order Suborder Infraorder Lemuriformes Strepsirhini
(lemurs)
Superfamily differences
Superfamily
Cercopithecoidea
narrow nasal opening narrow tooth rows 4 cusps molars bilophodont molars tail rel. long body rel. short arms
Hominoidea
broader nasal opening broader tooth rows 5 cusps molars (mandible) Y-5 pattern no tail rel. short, broad body long arms
Lemuroidea Lorioidea
Loriformes
(loris & galagos)
Primates Tarsiiformes
(tarsiers) Haplorhini
Tarsioidea
Platyrrhini
(New World monkeys)
Ceboidea Cercopithecoidea
Catarrhini
(Old World monkeys)
Hominoidea
(apes and humans)
Taxonomy of Catarrhine primates
Infraorder Superfamily Family Subfamily Tribe Genus Cercopithecinae Cercopithecoidea
(Old World monkeys) (cheek pouch monkeys)
Ape names and places
Grouped under
lesser apes
Genus
Hylobates etc. Pongo
Common name
gibbons & siamangs orangutans gorillas chimpanzees & bonobos
Area
Asia
Grouped under
Cercopithecidae Colobinae
(leaf monkeys)
Catarrhini Hylobatidae Hominoidea
(apes and humans)
Asian apes Asia Africa African apes Africa
Ponginae Hominidae Gorillinae Panini Homininae Hominini
Pongo Gorilla Pan Homo
great apes
Gorilla Pan
Lifestyles
lesser apes Genus Body size Diet Grouping
Hylobates etc. mediumsized fruits (leaves) Pongo
Partial list of tool use in great apes
great apes
Gorilla Pan (paniscus & troglodytes) large ( fruits leaves, animal matter) communities (fission-fusion)
large fruits (leaves) solitary (networks)
large herbs (& fruits) groups (>1 silverback)
pairs
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What you should know:
what are the concepts and foundations of primatology? what is an adaptation? why are we concluding that behavior is influenced by genes? what is sexual selection and how does it differ from natural selection?
Studying Primates
ANP 120 Lecture #20
what are the two forms of sexual selection?
Concepts in primatology
primates as referential models
to understand human behavior and evolution (behavior & morphology)
Foundations of primatology (1)
evolutionary principles
morphology & behavior as response to selective pressures
Evolution
genetic change through time (population level) by means of natural selection principle mechanism of Darwinian evolutionary change, by which the individuals best adapted to the environment contribute more offspring to succeeding generations than others do.
primates as models for behavioral evolution
to understand relationships between ecology, behavior, and evolution
Natural selection
Adaptation
the development of a trait that better suits an organism to its environment
improves chances of survival and reproduction usually result of natural selection
Adaptation
the development of a behavior that better suits an organism to its environment
improves chances of survival and reproduction usually result of natural selection
e.g., camouflage coloration
e.g., stereoscopic vision
e.g., carry not park
e.g., babysitting
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Genes and behavior
evidence for genetic influence
mutagenic agents interbreeding artificial selection experiments
Natural selection
favors traits that enhance ability to survive and reproduce
acts on ALL individuals
Sexual selection
category of natural selection favors traits that increase success in competition over mates
acts on individuals in ONE SEX only
Charles Darwin
Two forms of sexual selection
intrasexual selection
male-male competition
direct or indirect
Foundations of primatology
evolutionary principles
morphology & behavior as response to selective pressures
"winner" gets to mate
e.g., sexual dimorphism
scientific principles
scientific method & systematic sampling
intersexual selection
female choice "best" ones get to mate
e.g., male care selection of male qualities
What you should know: Primate Adaptations, I. Diet
what are the components of primate food? what are the major feeding categories? what is Kay's threshold? what are the major dental and gut adaptations related to obtaining and processing food?
ANP 120 Lecture #21
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Components of food
nutrients or "what to eat"
proteins carbohydrates lipids (fat) minerals vitamins water
Components of food
harmful or "what not to eat"
secondary compounds
tannins alkaloids
frugivore
eats mainly fruits (pulp, seeds)
folivore
eats mainly leaves (young, mature, or both)
insectivore (faunivore)
eats mainly insects (or animal matter)
gummivore
eats mainly gum
Body size and diet
omnivore
eats "everything", i.e., animals and plants
Kay's threshold:
insectivores upper limit is 500g folivores lower limit is 500g
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Dental adaptations: anterior teeth
frugivores folivores gummivores
Dental adaptations: posterior teeth
frugivores folivores insectivores
broad incisors
narrow incisors
stout incisors low, rounded molars shearing crests sharp cusps
Gut adaptations
"easy-to-digest foods" insectivores frugivores
Gut adaptations
"difficult-to-digest foods" folivores gummivores
enlarged caecum
enlarged colon
short, simple gut
long small intestine
complex stomach
enlarged caecum
What you should know: Primate Adaptations, II. Locomotion
what are the different forms of primate locomotion? what is the aim of functional morphology? what is the intermembral index (IMI) and what is expressed with it? what are adaptations to locomotion for the six main locomotor categories?
ANP 120 Lecture #22
what are the general IMI categories?
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Locomotor and postural behavior
the way primates move, hang, and sit
Leaping
move between branches or tree trunks
1. quadrupedal leaping use all four limbs
2. vertical clinging & leaping (VCL) propel w/ hind limbs
Quadrupedalism
1. arboreal
move w/ 4 limbs on branches (horizontal)
Quadrupedalism
2. terrestrial
move w/ 4 limbs on ground (hands/ feet flat)
Quadrupedalism
3. knuckle-walking
terr. q.; but hands cupped (knuckles on the ground)
Quadrupedalism
4. climbing
move w/ 4 limbs on vertical surface
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Suspensory locomotion
1. suspensory climbing
like climbing, but below horizontal surface (2, 3, 4 limbs)
Suspensory locomotion
2. brachiation
use upper limbs to swing body under horizontal surface
Suspensory locomotion
3. semi-brachiation
brachiation w/ suspensory climbing (plus prehensile tail)
Bipedalism
move w/ lower 2 limbs across horizontal surface
Functional morphology
relationship between form and function
adaptations to locomotion
shape of bones length & width of bones orientation of joints/ organs
Intermembral index (IMI)
ratio of limb lengths IMI = gorilla forelimb length hind limb length x 100
femur
mouse lemur
humerus radius tibia
IMI = How to compare species of different sizes?
length of humerus + length of radius length of femur + length of tibia
x 100
IMI < 100
IMI = 100
IMI > 100
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IMI = ca. 100 limbs similar length IMI < 100 long hind limbs short limbs walk with flexed limbs long tail grasping hand & feet IMI = ca. 100 limbs similar length long limbs shorter tail short fingers & toes shoulder joint restricted
quadrupedal leaper
long lumbar region
vertical-clinger-leaper
short lumbar region
Knuckle-Walker
IMI > 100 long forelimbs long limbs joints more rounded long & curved fingers short lumbar region
Knuckle-walking
IMI > 100 rel. long forelimbs retain suspension traits weight on dorsal surface of fingers
dermal ridges on dorsal surface
Terrestrial Quadruped
IMI < 100 long hind limbs dual curvature of spine short pelvis valgus knee foot not grasping
short toes big toe adducted
General IMI categories
leapers (VCL)
< 70
knuckle-walking
ca. 110
bipeds (humans)
ca. 70
brachiators
> 120
quadrupeds/ climbers
ca. 70 - 110
MUST take into account ancestry (comparisons within radiations)
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What you should know: Primate Social Systems, I. Group Life
what are the criteria by which primate social systems are defined? what is the activity pattern of solitary primates? what are the major benefits and costs for primates living in groups? how does group life lead to improved predation avoidance? how does living in groups increase the feeding competition within groups?
ANP 120 Lecture #23
Definitions
social organization
size & composition cohesion
Solitary
activity/ movements not synchronized almost all nocturnal several strepsirhines some tarsiers orangutans
mating system
who mates/ reproduces
social structure
patterns of social relationships
Pair/ group living
coinciding ranges & synchronized association variable levels of cohesion most diurnal several strepsirhines some tarsiers all NWM & OWM most apes
Major benefits & costs
benefits
living in groups
improved predation avoidance increased access to food (competition between groups) improved avoidance of coercion/ infanticide
costs
limit size of groups
more conspicuous (attract more predators) increased feeding competition within groups
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Predation avoidance
more individuals detect earlier (many eyes effect)
Predation avoidance
warning or protection of other group members
detection late
detection early
Predation avoidance
risk reduces with the number of prey (dilution effect)
Predation avoidance
group center safer than periphery (selfish herd effect)
risk = 1 of 1
risk = 1 of 4
Increased feeding competition
within groups
large groups: reduced energy intake per resource large groups: increased energy expenditure
Primate Social Systems, II. Social Organization & Mating Systems
Energy Expenditure
Energy / Resource
ANP 120 Lecture #24
Group Size
Group Size
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What you should know:
what are the four basic mating systems? what are the eight different social organizations/ mating systems distinguished for primates? what are the four major male mating strategies? what are the morphological consequences of male-male competition based on mating systems?
Defining mating systems
who mates [& reproduces]
monogamy
1 female & 1 male
polyandry
1 female & several males
polygyny
1 male & several females
polygamy
several females & several males
Pair living
"permanent" association of 1 male & 1 female w/ offspring monogamy
type 1 cohesive type 2 dispersed
Group living
association of > 3 adults (both sexes) w/ offspring
N males & N females level of cohesion mating system
note
often male care
Group living
1 male - multi female polygyny
Group living
multi male - 1 female polyandry note
type 1 individual groups type 2 multi-level
note
often all-male bands
1 breeding female & > 2 males non-breeding adults infant care by all members
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Group living
multi male - multi female polygamy
Solitary
male alone; female w/ offspring
activity/ movements not synchronized
type 1 cohesive groups type 2 fission-fusion
polygamy
type 3 dispersed
Male reproductive strategies
N offspring limited by access to females
find one, stay and help monogamy fight for & monopolize as many as possible polygyny fight for & mate with as many as possible polygamy mate with as many as possible polygamy type 3 (dispersed)
Sexual selection
favors traits that increase success in competition over mates
intrasexual selection intersexual selection
female choice
male-male competition
Charles Darwin
Male-male competition
fighting abilities
sexual size dimorphism
canine & body size
Mating systems & male morphologies
N offspring limited by access to females
find one, stay and help monogamy "no effect" fight for & monopolize as many as possible polygyny sexual size dimorphism fight for & mate with as many as possible polygamy large testes & dimorphism mate with as many as possible polygamy type 3 (dispersed) large testes
body size canine size
sperm competition
production & quality
M - multiple males, D - dispersed S - single male, P - paired
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What you should know: Primate Social Systems, III. Mating Systems & Social Structure
what limits reproductive success of females and what are their reproductive strategies? what is intersexual selection and what are females choosing? how is social structure defined and what factors are affecting social structure?
ANP 120 Lecture #25
what is dominance and how can it affect females and males? what is kin selection and how does it explain altruism and kin-directed behavior?
Sexual selection
favors traits that increase success in competition over mates
Female reproductive strategies
few offspring
food crucial
intrasexual selection
maximize access to food
primary strategy
male-male competition
intersexual selection
female choice
mate with the "best" male (female choice)
may gain reproductive benefits Charles Darwin
Female choice
select for male physical traits
indicating genetic quality making males more conspicuous
Social structure
patterns of social relationships
types of behavior organized along
age sex dominance kinship economic rules
select for male behavioral qualities
enhancing reproductive success (e.g., food, protection, care)
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Dominance
physical domination initiated and sustained by aggression or other behaviors (i.e., winning and loosing)
Female rank
regulates access to food
affects reproductive success
some species weak effects
food not monopolizable
Male rank
regulates access to females
affects reproductive success
Key questions:
how to explain preference for kin? how to explain altruism?
some species weak effects
Altruism
e.g., coalitions & bonding
behavior that reduces the reproductive success of the actor, at the same time increases the reproductive success of the recipient. W.D. Hamilton (1964) form of natural selection favoring (or disfavoring) survival & reproduction of relatives (excl. offspring)
Kin selection
Inclusive fitness
direct fitness
own reproductive success
indirect fitness
reproductive success of biological relatives
inclusive fitness = direct + indirect fitness
Good Luck !
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