Anthro 2B Final (Egan)

macro-evolution

evolution above the species level

micro-evolution

evolution below the species level

speciation

occurs when one species splits into two, which involves a reproductive isolating mechanism

example of reproductive isolation but NOT speciation

leopard frogs in Florida vs. Maine, can still reproduce but just can't because they are isolated; gene flow can happen

extrinsic isolating mechanism

factors producing geographic isolation which physically separates individuals (ex: movement of tectonic plates; mountains)

Intrinsic/ Pre-zygotic

no a physical barrier separation; this isolating mechanism prevents sperm from meeting egg; prevents zygote from ever forming

example of pre-zygotic isolating mechanism

different pine tree species produce pollen at different times of the year

post-zygotic

a zygote forms but might have a mutation that will cause it to die after

examples of post-zygotic isolating mechansim

infant can be born but is sick and dies; the resultant offspring is sterile!

fundamental principle of natural selection

rate of evolutionary change is directly proportional to the degree of variability in the population

corollary natural selection principle

fate of all evolutionary lineages is extinction; 99.9% of all lineages ever existing on Earth went extinct

anagenesis

change in a species over a long period of time; supports gradualism theory of evolutionary change

cladogenesis

sudden split results in formation of 2 species from 1 species; supports punctuated theory of evolutionary change

phyletic gradualsim

emphasizes anagenesis; slow change over time that leads to formation of a new species

punctuated equilibrium

emphasizes cladogenesis; evolutionary change from sudden speciation events

adaptive radiation

rapid expansion & diversification of a group of organisms as they adapt to a newly available ecological space; involves rapid speciation/cladogenesis; occurs from new changes that open up potential new habitats to a group of organisms

what type of theory of evolutionary change does a phylogenetic tree model?

the punctuated equilibrium theory of evolutionary change

example of adaptive radiation

South American finch goes to Galapagos Islands (species with HIGH adaptive potential invades a new local)

another example of adaptive radiation

mutations produce major adaptive shift such as the evolution of the amniotic egg; mutations give you a new way of using an environment that no one else has

generalized

species able to exploit a wide range of ecological space; a jack of all trades and ace of none

specialized

species are specialized to a narrowly defined eco-niche; ace of one trade

generalized vs. specialized species

generalized species tend to start adaptive radiation and have more potential to survive/adapt; when species specialize, competition can cause speciation

evolutionary homology

useful similarity; similarities in structures due to COMMON ANCESTRY; their similar structures have DIFFERENT functions

example of evolutionary homology

human arm & bat wing are similar shapes and FUNCTION DIFFERENTLY

evolutionary analogy (homoplasmy)

independent evolution; didn't come from same ancestor; misleading; structures have SIMILAR FUNCTIONS - use this when making phylogenetic tree

example of evolutionary analogy

bird wing and fly wing; both fly but are not from the same ancestor

2 types of evolutionary analogy

convergence & parallelism

convergence (a type of evolutionary analogy)

drastically unrelated organisms

(ex: squid eye vs. human eye); not the same ancestor but eyes have same function - MISLEADING

parallelism (a type of evolutionary analogy)

closely related organisms (ex: incisors in lemurs & Goeldi's monkey) - in the same order but evolved independently in both species

primitive/ancestral traits

a trait retained in its ancestral form (polydactylyl; maintenance of 5 digits)

derived traits

trait that has been modified from ancestral form thru alterations via mutations (gain, loss, or change of function); (ex: claws turn into nails; claws turn into hooves)

shared derived traits

still just a derived trait, but know it is shared across species (ex: cloven hoof found in cows, goats, deer, etc.)

what are characteristics of the Primate order

1. emphasis on vision/color vision

2. reduced snout

3. auditory bulla

4. prehensile hands/feet (precise grip)

5. larger brain/increased cerebral cortex

6. decreased litter size

7. post-orbital bar or septum

post-orbital bar

a skeletal structure in form of a bar of bone, behind the eye that does not close it off (strepsirrhines)

post-orbital septum/closure

P-O septum (partial p-o bar); eye socket is entirely protected by bone; P-O closure is when it is fully closed

Who has a P-O bar/P-O septum?

strepsirrhines have a P-O bar, haplorrhines have a partial/closed P-O septum

-simiiformes have full P-O closure

binocular/stereoscopic vision

2 eyes positioned facing forward; overlapping fields of vision; both eyes focus on an object/eyes are in front of head; eyes send stimulatory signals to both hemispheres of brain; provides depth perception

color vision

abundance of cones in eyes; nocturnal primates are exception; diurnal/crepuscular(twilight) organisms usually have color vision

night vision

abundance of rods in the eye (not cones); allows nocturnal organisms to see at night

Who is nocturnal/who isn't?

Lorisiformes (under strepsirrhini) and Tarsiiformes (under haplorrhini)

Lemuriformes are NOT nocturnal

auditory bulla

skeletal chamber which holds the tiny bones of the middle ear

K-selection

a reproducing strategy where parents lay little offspring and give extensive care to their babies; constant population

- this is the type of reproducing strategy in primates

R-selection

a reproducing strategy where parents lay numerous offspring and have them survive if they can; no parental care; population number varies

visual predation hypothesis

the proposition that unique primate traits arose as adaptations to preying on insects and on small animals; catching of small prey using specialized vision and motor skills set primate evolution in motion

Where are lemuriformes from?

Madagascar

Where are the lorisiformes from?

Africa/Asia

Where are the tarsiiformes from?

South-East Asia

Where are the Platyrrhini (New World Monkeys) from?

South America

Where are the Catarrhini (Old World Monkeys) from?

Africa/Asia

Where is the Hylobatidae from (Hominoidea)

SouthEast Asia

the only species in the Hominidae that is not found in Africa; and where is it found?

the Orangutan (Pongae) is found in sumatra/borneo

Where are the rest of the hominidae found?

gorilla, homininae (panini) found in Africa; hominini found everywhere (humans!)

Dental formula

ICPM

#incisors:#canines:#premolars:#molars

frontal bone

bone that forms part of a skull and the upper part of the eye sockets

Who has a fused / unfused frontal bone?

Strepsirrhines have unfused frontal bone while simiiformes (haplorrhines) have a fused frontal bone

mandibular symphasis

lower jawbone

who has a fused/unfused mandible?

strepsirrhines and tarsiiformes (haplorrhini) have an unfused mandible and simiiformes (haplorrhines) have a fused mandible

dental comb

mandible incisors (lower jaw front teeth) are specialized for grooming and feeding; also projects to the front of the mouth

who has the dental comb

strepsirrhini

rhinarium

external moist membranes in the nose

who has a rhinarium/wet nose?

strepsirrhini (as opposed to the haplorrhini who have dry noses)

toilet claw

claw used for grooming

who has a toilet claw?

strepsirrhini and tarsiiformes

TEST: characteristics of catarrhini regarding:

1) P-O

2) dental formula

3) nostrils

4) mandible

they are under haplorrihini and simiiformes:

1. full P-O closure

2. 2-1-2-3

3. narrow nostrils

4. fused mandible

prehensile tail

tail that can be used for grabbing objects

who has the prehensile tail

Haplorhinni > Simiiformes > Platyrrhini > CEBOIDEA

twin births

monozygotic but not identical; common in Ceboidea/caltrichidae

canine diastema

gap in a tooth row to accommodate the canine tooth so mammal can close its mouth/chew

CP3 complex

large canines; example of sexual dimorphism: much larger in males than in females; goes with diastema

ischial callosities

thick piece of skin found on buttocks

who has ischial callosities?

Haplorrhini > Simiiformes > Catarrhini > CERCOPITHECOIDEA

and

Haplorrhini > Simiiformes > Catarrhini > Hominoidea > HYLOBATIDAE

Bilophodont Molar Pattern

4 cusps on the molar; lower molars have 2 ridges

Y-5 Molar Pattern

5 cusps on the molars

who has the Bilophodont Molar pattern?

Haplorrhini > Simiiformes > Catarrhini > CERCOPITHECOIDEA

who has the Y-5 molar pattern?

Haplorrhini > Simiiformes > Catarrhini > HOMINOIDEA

Estrus/Estrus Swelling

females go thru estrus, part of the menstrual cycle

sexual dimorphism

average difference in body size between adult MALES and FEMALES that distinguish the two genders

IMI

intermembral index = (arm length/leg length) *100

Body size - IMI (types of locomotion)

-IMI < 100, small body size, vertical clinging/leaping, arm shorter than legs

-IMI = 100, medium, quadruped, all fours, arm = legs

-IMI > 100, large, suspensory/brachiation, arms longer than legs

Hominoid/Quadruped Anatomical Contrasts

Hominoids:

-brachiators anatomy

-short legs, long arms

- IMI > 100

- larger primates swing

- no tail

Cercopithecoidea:

-quadruped anatomy

-narrow, deep thorax

-limited rotation in shoulders

-limited extension of forearms

-limited flexibility in wrists

-arms and legs same length

- IMI = 100

- tail

who does fist walking?

Ponginae (Orangutan)

who does knuckle walking?

Gorillinae (chimps/gorillas) and Panini (under homininae)

Diurnal

awake during the day

Nocturnal

awake at night

Crepuscular

awake during twilight, lit moon

Body Size - Diet Relationship

small body vs. large body

small body <500g: fast metabolism; eats proteins/fats/insects/sap

large body >500g: slower metabolism; eat mature leaves

Locomotion - Body Size Relationship

small body vs. large body

small body: run on top of branches, leap, IMI = or < 100

large body: hang under branches, swing, IMI > 100

Monogamy

a form of primate social organization; males and females mate; less sexual dimorphism

ex: tarsiers, tarmarins, marmosets

single-male/uni-male groups

1 adult male, many females

Whose social organization is a uni-male or single male group?

Gorilla

"Silverback Male"

multi-male/female group

many adult males and females

whose form of social organization is multi-male/multi-female?

chimpanzees and lemurs

what different types of social organizations do lemuriformes have?

Multi-male/female

monogamy

solitary

what type of social organizations do lorisiformes have?

solitary

ecological niche

role and position a species has in its environment; HOW it meets its needs for food & shelter, survives, and reproduces

territory

INSIDE a home range; an area aggressively defended against intrusion, especially intrusion by con-specifics

home range

total area used by an organism or a social group of organisms; all the area they explore

behavior ecology/socio-ecology

behavior within environment

social organization: means by which organisms adjusted to their environments; relationship between environment and social behaviors

sociobiology

-natural selection & alleged genetic bases of social behavior

-study of whether genes control social behavior

Infanticide among Langurs

-male drives out other male and kills all of that male's infants

-then mates with the females to create its own offspring and increase its own fitness