ANTH 2502 UCONN EXAM 1

Charles Darwin

-formulated theory of evolution/natural selection

Darwin's three postulates

1. the ability for a population to expand is infinite, but the ability for an environment to support populations is always finite

2. organisms within a population vary, and this variation affects the ability of individuals to survive and reproduce

3. variation is transmitted from parents to offspring

morphology

organisms size, shape, and composition- can change over time so that the organism can adapt to their environment

Gregor Mendel

-"father of modern genetics"

-experimented with pea plants (color-green or yellow, & texture- wrinkled or smooth) which eventually led scientists to discovery of alleles

alleles

different varieties of a single gene (can be dominant or recessive)

homozygous

having two identical alleles for a particular gene

heterozygous

having two different alleles for a particular gene

genotype

an organism's genetic makeup, or allele combinations

phenotype

physical characteristics of an organism

4 characteristics of natural selection*

1. sexual reproduction produces VARIATION

2. some offspring are better suited to environmental conditions than others

3. those that are better suited to environmental conditions will produce more offspring than others (fitness= reproductive fitness)

4. over many generations there is enough change produced that a new species is produced

all species are a combination of:

1) primitive traits

2)derived traits

primitive traits

adaptations of the past (ex. pentadactyl)

derived traits

adaptations to recent timed (ex. bipedalism)

what are the 5 primate characteristics?

Primitive body plan

Dental formula

Grasping hand and foot

Increased reliance on sight

Less reliance on smell

K selected

what does primitive body plan consist of?

-one bone in upper limb

- two bones in lower limb

-five digits on hands and feet

what is a primate's dental formula?

2-1-2-3 or 2-1-3-3 (incisors-canines-premolars-molars)

hederodant

hederodant

dental formula of primates, teeth are in different positions in jaw and have different functions

homodant

dental formula found in reptiles, teeth all have same shape and function

2-1-2-3 dental formula

old world monkeys, apes humans

2-1-3-3 dental formula

prosimons, new world monkeys

K versus R selected

- K selected: few offspring, large investment

- R selected: many offspring, small investment

altricial young

offspring that is completely helpless after birth and dependent on their parents

precocial young

offspring born in a relatively mature state, eyes open

where do most primates live?

in the tropics, near equator

arboreal

living in trees (nearly all primates are arboreal)

biological species concept

if two animals can interbreed, they're part of the same species

arboreal hypothesis

the proposition that primates' unique suite of traits is an adaptation to living in trees:

1. grasping hands and feet

2: stereoscopic vision

ape characteristics

larger body size, longer lifespan, longer interbirth interval, upright posture, larger brain, shorter muzzle, no tail, increased reliance on vision

function of incisors

cutting food/taking a bite

function of canines

tearing food/killing your meal/defense and display (bigger in males)

function of premolars and molars

grinding and crushing

bunodont molars

low crowned, rounded cusped molars present in frugivores or omnivores

hypsodant teeth

(seen in horses) high crowned, used especially for grass or leaf eating

lophodant or selenodant

complex cusps, used especially for grass or leaf eating

carnassials

slicing molars and premolars present in carnivores

frugivore

fruit eaters

-big incisors

-bunodont molars

-short gut

folivores

leaf eaters

-small incisors

-sharp, high/tall crowned molars &premolars

-long gut

carnivore

meat eater

-small incosors

-large canines

-carnassials

-short gut (meat= high quality, dense in protein)

omnivore

(generalists - eat anything)

-large incisors

-bunodont molars

-canines variable

-short to medium gut (humans known for short gut)

Milutin Milankovitch

scientist who discovered astronomical forcing of global climate

steps of astronomical forcing of global climate

1.changes in shape and orientation of earth's orbit

2. differences in distance and angle between earth & sun

3. changes in amount of solar radiation reaching earth

4. changes in global climate

Linnaeus

proposed a new system of organization for plants, animals, and minerals, based upon their similarities- binomal nomenclature

-taxonomy (classification of organisms)

binomal nomenclature

the naming system for organism in wich each organsim is given a two part name-a genus name of different species in an area

(ex. homo sapiens

uniformitarianism

a theory based on the work of James Hutton and made popular by Charles Lyell in the 19th century. This theory states that the forces and processes observable at earth's surface are the same that have shaped earth's landscape throughout natural history.

microevolution

small changes within a population over a short period of time (change in gene frequemcies

macroevolution

large changes within a population over a long period of time (extinction or creation of new species)

7 mechanisms of microevolution that change allele frequencies

1)natural selection

2)mutation

3)genetic drift

4)population bottleneck/ Founder Effect

5)assortative mating

6)inbreeding

7)gene flow (migration)

what is mutation?

change in DNA sequence, appearence of new alleles

what is genetic drift?

variation in the relative frequency of different genotypes in a small population, owing to the chance disappearance of particular genes as individuals die or do not reproduce.

what is the founder effect?

shows that allele frequencies in small founding population may not represent those in parent population

what is assortative mating?

when individuals mate with those who are similar to themselves

what are the effects of inbreeding?

more likely to look alike & inherit double copies

what is gene flow/migration's microevolutionary effect?

population movement introduces new alleles

4 kinds of macroevolution evolutionary events

1) stasis

2) extinction

3) anagenesis

4) cladogenesis

stasis in macroevolution

species lineage shows NO change

extinction

termination of species

anagenesis

gradual modification of form over evolutionary time, without branching speciation

cladogenesis

BRANCHING SPECIATION the formation of a new group of organisms or higher taxon by evolutionary divergence from an ancestral form.

allopatric model of speciation

(other land model) species becomes isolated geographically and changes in its own way as it evolves

sympatic model of speciation

species live in same area but use different resources (niche partitioning) ex. finches

isolating mechanisms include

1) morphological differences

2) genetic incompatibility

3) behavior

4) mate recognition (SSMRS)

examples of isolating mechanism behavior

- posture: exhibits willingness to mate

-vocalizations

convergent evolution

process whereby organisms not closely related (not monophyletic), independently evolve similar traits as a result of having to adapt to similar environments or ecological niches.

convergent evolution example

the wings of bats and birds

DNA hybridization

the process used to compare structural characteristics of organisms to determine how closely related they are

DNA hybridization process

1. extract DNA

2. cut double helix strands by heating

3. reform double helix by connecting the different DNA into "hybrid strands"

4. determine melting temp and calculate difference

molecular clock

model that uses DNA comparisons to estimate the length of time that two species have been evolving independently

fossil

mineralized remains of animal or plant (usually bones or teeth)

trace fossil

sign of animal's or plant's interaction with the environment (ex. footprints or burrows)

artifact

any object made or modified by hominins (ex. stone tools)

types of rocks

1. volcanic rocks

2.sedimentary rocks

3. metamorphic rocks

volcanic rocks

derived from molten crust

-dateable by potassium/argon and argon/argon dating

-source for toolstone

sedimentary rocks

composed of particles of other rocks (ex. sandstone)

-contains fossils or artifacts

metamorphic rocks

sedimentary rocks transformed by heat or pressure (ex. marble)

kinds of volcanic rock

1. magma - underground

2. lava - extruded at surface

3. ash - exploded into air (tephra or tuff, pyroclastic flow)

volcanic ash (tuff, tephra)

records single instant in time

-dateable by K/Ar & Ar/Ar

- excellent for correlating among sites

loess

(ex. of sedimentary rock) Eolian deposit- windblown silt

particle size in sedimentary rocks

reflects energy in sedimentary environment (how much energy is required to transport particles)

mudstone,shale -> sandstone -> conglomerate (pebbles, cobbles, boulders) ..... low energy -> high energy

law of superposition

Nick Steno- law that states the layers at the top are the youngest and those on the bottom are the oldest layers (strata)

lithostratigraphic vs biostratigraphic correlation

lithostratigraphic: strata collected based on rock type

biostratigraphic: strata collected on basis of fossils they contain

radiocarbon dating

-type of radioactive dating measures decay of 14C into 14N

-half life: 5730 yrs

-approximate limit of 50,000 years

argon-argon dating

A high-precision method for estimating the relative quantities of argon-39 and argon-40 gas; used to date volcanic ashes that are between 500,000 and several million years old

when did africa and eurasia connect?

17 ma

when did continents reach modern position?

17 ma

common isotopes of oxygen

18O - in cold periods, sea water is higher in 18O (heavy)

16O- ice takes up 16O (lighter)

Milankovitch effects

changes in:

-temperature

-rainfall

-vegetation

-glaciers

-sea level

what is gene flow/migration's microevolutionary effect?