exam 2 Flashcards
do individuals evolve
individual don’t evolve populations do
what results from natural selection
traits that are best suited for the envt
how does fossil formation work
sediment carried from rivers to swamps where organisms are buried
strata
layers of sediment
fossil record
chronological appearance of fossils in rock layers
youngest layer on top
what does the fossil record testify
organisms appeared in a sequence
how old are the oldest fossils and what are they
3.5 byo, prokaryotes
order of evolution of organisms
prokaryotes -> eukaryotes -> fish -> amphibians -> reptiles -> mammals
what did Darwin notice on the Galapagos islands
finches were more similar to finches on the mainland than to finches on other islands
adaptive radiation
evolution by being separated from ancestor, ex being separated on islands
comparative anatomy
comparing body strx between diff species
homology
similar strx due to a common ancestor
comparative embryology
comparison of strx that appear during the earliest stages of development
according to comparative embryology, what do mammal, fish, bird, and reptile embryos all have in common
segmented muscles, tubular heart, gill pouches
molecular biology
comparison of genes and proteins between diff species
directional selection
natural selection favors one extreme, shifting bell curve
diversifying (disruptive) selection
natural selection favors two extremes, bell curve splits down the middle
stabilizing selection
natural selection favors the middle and extremes die off, bell curve gets thin and tall
what kind of habitats lead to disruptive selection
patchy habitats
what kind of habitats lead to stabilizing selection
Habitats that are relatively stable and consistent over time, with minimal environmental fluctuations
what kind of habitats lead to directional selection
Habitats that are undergoing significant environmental changes
gene flow
flow of genes in a population
what does gene flow lead to
genetic diversity
two mechanisms of gene flow
migration, sexual reproduction
genetic drift
random change in allele frequencies in a population
what effects lead to genetic drift
founders effect, bottleneck effect
what did Ernst Mayr do
invented the biological species concept
identified 138 species of birds when the indigenous people only identified 137
what is BSC based on
reproductive compatibility rather than morphological similarity
what is a prezygotic barrier
reproductive barrier that prevents fertilization
post zygotic barriers (2)
- sterile offspring
- hybrid inviability: offspring die before maturity
pre zygotic barriers (4)
- behavioral: diff mating behavior
- mechanical: strx difference in sex organs
- habitat isolation
- temporal: diff mating times
how many species exist and how many have been discovered
what animal are most species
5-30 mil exist and 1.8 mil discovered
mostly insects
what does habitat isolation lead to
speciation
what species are the hardest to identify
inconspicuous forms like bacteria
allopatric speciation
speciation from geographic isolation
sympatric speciation
speciation from reproductive isolation
how does sympatric speciation occur
a population becomes reproductively isolated in the middle of the parent population or mutation
what organisms does sympatric speciation occur in and why
plants because of changes in chromosomes
speciation
the formation of two or more genetically distinct groups
Precambrian era (4.6 bya-570 mya)
earliest living organisms - algae, bacteria, invertebrates
Paleozoic era (570-245 mya)
ancient life- early plants, fish, amphibians, insects, reptiles
Mesozoic era (245-65 mya)
gymnosperms, angiosperms, dinosaurs, mammals, birds
Cenozoic era (65 mya-present)
first primate groups
why is human-induced environmental change harmful
life on Earth evolved slowly, so when we speed up environmental change, life can’t keep up, and we get species extinctions
systematics
the study of biodiversity
what did Carroleus Lineaus create
binomial nomenclature
binomial nomenclature
capitalize Genus, italicize species
Higheraechial classification
D, K, P, C, O, F, G, S
did king phillip come over for good sex
3 domain system
bacteria, archaea, eukarya
Biogeography
The geographic distribution of species
Related species are found in close proximity to each other
two examples of natural selection from class
spotted pepper moth and pesticide resistance
mutation
An error in cell reproduction will sometimes change the DNA.
produces a change in inherited characteristics
allopatric speciation example from class
Antelope squirrels in the Grand Canyon
sympatric speciation example from class
wheat
Parapatric Speciation
when a species evolves into two distinct groups while still exchanging genes. This happens when a population is spread out over a large area
Domain Bacteria
prokaryotic, asexual reproduction
Domain Archaea
more similar to eukaryotes, extremophiles, unicellular
kingdom fungi
nonmotile, heterotrophic by absorption of nutrients
kingdom plantae
autotrophic by photosynthesis
kingdom animalia
heterotrophic by consumption, well developed tissues, motile
kingdom protista
not a plant, animal, or fungus
principle of common descent
species branched off from a common ancestor
phylogeny
evolutionary history
clade
common ancestor + all descendants
primitive characteristics
characteristics derived from a common ancestor
derived characteristics
new characteristics
toxicology
study of poisons
pollution
The addition of a chemical or physical agent to the air, water, or land
ecotoxicology
environmental poisons
contamination
unfit for human use
benzo pyrene
carcinogen and mutagen
tetragen
increases the risk of birth defects
ex: accutane
synergism
the combined effect of two chemicals is greater than the sum of the separate effects
what do heavy metals do between trophic levels
biomagnify
what caused the disease of the dancing cats
mercury was dumped into waterways, became methyl mercury, biomagnified
disease of dancing cats takeaways (4)
- individuals vary in their response to certain doses
- pollutants may have a threshold
- some effects are reversible
- chemicals can get altered in the envt
ppm
parts per million
ppb
parts per billion
what does micrograms per cubic meter measure
air
what does mg/l measure
water
what does 1 mg/l equal
1 ppm
what are the infectious agents (7)
heavy metals, toxic chemicals, natural and synthetic organic compounds, industrial pollutants, radiation, heat, particulate matter
what are persistent organic pollutants
synthetic compounds, often containing Cl, that don’t easily break down in the envt
organic compounds
made of carbon
what are synthetic compounds used in
industrial processes
hormonally active agents
Chemicals in the environment able to cause reproductive and developmental abnormalities in animals
general effects of pollutants (5)
Changes in Abundance
Changes in Distribution
Changes in Birth Rates
Changes in Death Rates
Changes in Growth Rates
LD-50
amount of a toxin is enough to kill 50% of the population
ED-50
the concentration of a toxin that causes some kind of response in 50% of the population.
TD-50
dose of a toxin that is toxic to 50% of the population
acute exposure
sudden exposure to a large dose, severe reaction
chronic exposure
long term exposure to low levels
dose
amt of a chemical that an organism is exposed to
response
bodily processed occurring bc of the effect of the toxin
maximum benefit plateau
the highest dose of a substance that can be administered without causing adverse effects or death
threshold
amount of a chemical, below which there are no observable effects, but above which effects become apparent
tolerance
reduced response to a toxic substance after repeated exposure
Behavioral Tolerance
when an organism learns to modify its behavior to minimize the effects of a toxic substance
ex: getting good at drunk driving
Genetic Tolerance
inherited resistance to a toxic substance
ex: pesticide resistance
Physiological Tolerance
a gradual decrease in the body’s response to a substance due to repeated exposure
ex: the more you drink, alcohol the more you need to get drunk
4 steps of the risk assessment test
- identify the hazard
- perform a dose response assessment
- perform an exposure assessment
- perform a risk characterization
precautionary principle
when you’re unsure of a threat, the biggest risk is doing nothing
we should still take envtl precautions, even when were not certain of the threat
what has happened to US forests over time
they have declined in quantity and in quality
Biome
Defined by the climate and the dominant vegetation.
where are Temperate rainforests found
Northwest US, southeastern Australia, Southern South America
what are Temperate rainforests defined by (4)
50+ in of rain annually, mild climate, spruce and epiphytes, nutrient rich soil
where are Temperate deciduous forests
eastern North America, northeastern Asia, western + central Europe
what are Temperate deciduous defined by (4)
moderate climate, well defined seasons, 30-60 in of rain, broad leaf trees
Tropical rain forests
warm/moist climate, 79+ in rain, rich biodiversity, nutrient poor soil
Tropical dry forests
two seasons: rainy and dry
trees shed leaves in dry seasons
what is the largest terrestrial biome
boreal/ taiga
where is the boreal/ taiga biome
South of the tundra and at cool high elevations
what is the boreal/ taiga biome characterized by (5)
low temp, nutrient poor soil, snowy, conifers and evergreens, low biodiversity
photosynthesis formula
6CO2 + 6H2O → C6H12O6 + 6O2
which way is primary growth
upwards
which way is secondary growth
sideways
biomass
living material/ plant tissue
xylem
transports water upwards
phloem
transports photosynthesis products downwards
Primary productivity
the rate at which producers build biomass
cambium
layer between xylem and phloem, 1 cell thick
evapotranspiration
evaporation from soil and leaves
ecological functions of a forest (4)
regulate temp, evaporate water to reduce runoff, absorb carbon, slow wind
what are the 4 US forests
Temperate Deciduous Forest, Temperate Rainforest, Costal Pine Forests, Rocky Mountain Pine Forests
what are the 2 giant US forests
Coast Redwood: coastal California
Giant Sequoia: inland on the western slopes of mountains
3 characteristics of giant forests
insect/fire resistant, high rainfall, basal burns
what is the perfect condition for a forest
theres no single set of perfect conditions for a forest
traditional forest management
commercially desirable species, monocultures, pesticides
Ecologically Sustainable Forest Management
mix of trees, conserves habitats, protects soil and water quality, uses wildlife corridors to encourage gene flow
where did deforestation take place historically (5)
east US, ancient greece, roman empire, medeval europe, near east
where is deforestation an issue now, how many acres a year
south america, 4.3 milion
causes of deforestation
settlement, agriculture, fuel, paper
indirect deforestation
death of trees from pollution and disease
indirect deforestation causes
acid rain, smog, bad air quality
clear cutting
removal of all trees without regard to size or species
problems with clear cutting
BAD!!!!!
increases erosion, soil decays faster
shelterwood cutting
remove undesirable trees
seed tree cutting
leave behind seed trees
selective cutting (thinning)
only cutting a certain size or species
strip cutting
cut forest in rows
chip mills
large areas of forest that are clear cut, trees are used to make chips
what are chip mills for
used for paper, land is burned for planting
what trees are planted at chip mills, why is it bad
loblolly pine seeds, reduces diversity
why are invasive species bad for forests
contributes to indirect deforestation
invasive forest species in the US
chestnut blight, dutch elm disease, wooly adeglid, asian longhorn beetle
what is the fundamental question of forestry
how can we achieve sustainable forestry
naturalization
establishment of wild population
requirements for the naturalization of an invasive species
find suitable habitat, escape predators, disease, parasites, outcompete native species
facilitation
spread of invasive species pop
where do invasive species facilitate the best
disturbed ecosystems, urban and agricultural areas
what ecosystems are the most susectpible
disturbed and island ecosystems
where have invasive species been exponentially increasing
everglades
top 3 threats to biodiversity
habitat loss, overexploitation, invasive species
burmese python
endangered in india and china
menace in the everglades
exotic species
one species that is translocated from one geographic region to another
problematic invasive characteristics
generalists, reproduce quickly, small body size
how do invasive aquatic species get introduced
balast water, attach to ship
reasons for intentional introduction
agriculture, hunting, soil erosion control, biological control, fur trade
effects of invasive species
- competetive exclusion
- diseases
- genetic swamping
- reorganize ecosystem
competetive exclusion example
russian ecologist gregory with protists
diseases from invasives in the US
asian tiger mosquito: west nile virus
genetic swamping
genes of invasive ruin natural gene pool
how can we prevent the entry of invasives into the country
treat ballast water at port, exchange ballast water in the ocean, fumigate cargo
how can we control the spread of invasives
pesticides, hunting, biological control
biological control example
parastic fly introduced to control spotted gypsy moth
