Exam 1 Flashcards
what are the main limiting factors
insolation, temperature, elevation, moisture
the most important component that inhibits biological operations through its lack or excess
limiting factor
global variations in insolation by latitude
further away from the equator the less light received, more oblate angle of insolation
sun loving, grow best in full light
heliophytes
shade loving, grow best in shade
sciophytes
have small, thick leaves, slightly curles, reflective or waxy covered, larger number of stomata, orientation, furry/hairy, light coloring, spines instead of leaves
heliophytes
have large, broad leaves and more chlorophyll
sciophytes
temp moderated by proximity to ocean
maritime and continentality effect
temp decreases as elevation increases
lapse rate
take on the temp of their environments
poikeliotherms
.
C3 photosynthesis
.
C4 photosynthesis
.
CAM photosynthesis
animals that maintain stable temp through metabolic generation
homeotherms
adaptations to temp for hot conditions
sweating and panting
adaptations to temp for cold conditions
fat and thick coats or fur
the length of extremities like ears and arms increase with increasing temp
allen’s rule
does windward or leeward have more moisture
windward
low moisture adaptations, dry environments
xeric
water stress avoiders, will go dormant, drop leaves, hard waxy cuticles, deep or extensive roots, water storage strategies, spines, nighttime photosynthesis
xerophytes
mod-high moisture adaptations, have shallow, broad root structures for stability, dense plant stability, high net primary productivity
mesic
high moistures, flooded often
hydric
high tolerance for temp and soil moisture
generalists
low tolerance range for limiting factors
specialists
generalist species example, wide range of moisture and temp, wide range in the us
red maple
specialist, low tolerance, confined range of the pacific northwest
coastal redwoods
generalist species, for nesting and feeding, ranges vary seasonally with temp, most of north america
mallard duck
specialist, low tolerance, limited by habitat needs of itself and its food source- apple snails,
snail kite
Group of similar organisms capable of interbreeding and reproductively isolated from other groups
biological species concept
Group of organisms of a
similar species
population
“an assemblage of all species and their populations which occur together in a particular area and interact with each other and their surroundings”
community
diversity, density, composition, and
biomass
community structure
dynamic properties of relationships,
behaviors, competition, resource use, interactions, and activities
that affect energy flow and nutrient cycling
community function
all the species, all the features of that place’s
physical environment, and all the interactions between
the biotic and abiotic components of the system
ecosystem
Self-regulating association of living (and dead)
organisms and their nonliving physical and chemical
environment
ecosystem
ecosystems are scale…
independent, depends on unit of analysis,
organisms, or process of interest
Physical location within an ecosystem occupied by an organism, population, or community, and the resources the organism requires
habitat
Function or “occupation” of an
organism within a community,
how it uses resources and
contributes to the ecosystem
niche
Major ecosystem type
“Emphasis on the regional scale, and on the
significance of global climate and edaphic
controls on biotic communities”
biome
major terrestrial biomes
.
Smaller unit of analysis than Biome
ecoregion
Part of an organism that can disperse
propagule
flora propagule
seed, leaf, branch, spores
fauna propagule
reproductive pair or small groups of animals, eggs
Propagule must be able to
establish a viable reproducing
population to survive
Occurs when a propagule arrives in an area
previously unoccupied by the species and
establishes a reproducing population
colonization
Physical limiting factors Habitat resources Food and nutrients Competition Predation
factors that can impede colonization
within ecosystem and habitat dispersal
intra-range
regional dispersal across larger area
extra-range
intra-range is usually
Specialist, low tolerance to limiting factors
Limited by habitat needs and food source – apple
snails and apple kites
extra-range is usually
Higher tolerance to range of varying conditions
Range expansion into new areas
Generalist for nesting and feeding
Range may vary seasonally with temperatures
Common with disturbance tolerate species,
invasives, and exotics
of individuals that an environment can support
carrying capacity
carrying capacity is a resource…
dependent measure
number of different species
diversity
who and what
composition
number of individuals
density
once CC is reached,
competition increases and population growth slows
if there is rapid growth greater than cc, this may result in
catastrophic decline and exploitation of resources
Spread to adjacent areas close to the source
diffusion
slow diffusion example
Armadillo – central Mexico into mid- and
eastern- US, hundreds of years
fast diffusion example
Starling – NY to Pacific Coast in
Away from range limits to a new area
Island colonization
Often transported by supplemental means
jump dispersal
pattern of range expansion: initial rate is
Initial rate is often slow, rate increases as
population grows toward carrying capacity
pattern of range expansion: population
builds, species expands
pattern of range expansion: growth and range expansion
limited by env, and bio controls
pattern of range expansion: carrying capacity is
met and population fluxuates
passive dispersal
plants
active dispersal
animals
wind blown, light, aerodynamic, wing and fan
anemachores
water dispersed, on water surface, hydrophytes
hydrochores
animal dispersal, internally defecate, and external in burs,
zoochores
gravity dispersed, drop from plants, rounded
barochores
moved by humans
anthropochores
species with high dispersal and colonization among a variety of different habitat types, early colonizers after a disturbance
supertramps
the area around its home / territory
that is used for feeding and other daily activities,
often shared with other species
homerange
the area defended against intrusions by
other individuals of the same species
territory
one way movement of an individual
from its home range where it was born to a new
home range
dispersal
the cyclic movement of animals
between separated areas that are used during
different seasons for different life stages
migration
migration can be
latitudinal, vertical. upstream or downstream
reasons for migrating
food, temp, safety, reproduction, but most tied together
Genetically controlled changes in physiology and behavior
evolution
change within a species
micro evolution
change within a taxonomic group
macro evolution
Development of two or more genetically differentiable species from a single common ancestor species
speciation
different species from the same ancestor
clade
speciation results from
evolutionary change, but not all evolutionary change results in development of two or more species
Total genetic message in a cell or individual, genotypic variations control phenotypic variations between different species
genotype
expression of a genetic message - variation in morphology, physiology, behavior of different species or variation with same species
phenotype
variation of appearance within a pop
polymorphism
geographic gradient in a genetically controlled trait
cline
Creation of new alleles and chromosome structure
genetic mutations
As new genes form over time, some are mutated, others are lost – these ‘chance’ changes can lead to development of new species through process of
genetic drift
genetic drift is usually successful when pop is
smalla nd geographically isolated or isolated by range limits
Event or catastrophe reduces the population size and the remaining survivors influence the allele diversity of the next reproducing generations.
bottleneck effect
Promotes certain beneficial traits and represses others
natural selection
Promotes certain beneficial traits and represses others
adaptive radiation
formation of new species by geographic isolation
allopatric speciation
rapid speciation with isolated populations
founder principle
occupy same type of habitat but separated by a barrier and thus speciation can occur
peripatric speciation
formation of new species in same geographic area
sympatric speciation
evolutionary divergence of species in same area occupying different habitats
parapatric speciation
finches are an example of
jump dispersal that led to allopatric speciation to multiple species on the hawaiian islands
chiclids are an example of
sympatric speciation
how does adaptive radiation occur
differences in life cycle timing, adaptions to environmental gradients, behavior recognition of courtship activites
theory of phyletic gradualism
Speciation is slow, uniform, and gradual
New traits arise by mutation
Traits with greater reproductive success are selected
Dominant traits and genetic change can take multiple generations but follow single line of decent
theory of “quantum evolution” punctuated equilibrium
Many evolutionary changes occur in small populations at periphery of species ranges or in isolated areas
If changes occurring at periphery are beneficial, they may spread quickly, producing rapid genetic change
Periphery areas = gradients between different environmental conditions = more selective pressure for beneficial traits
Evolution and Organism Complexity
Darwin - single cell organisms as “lower”, multi-cell as “higher”
problems with darwins view of complexity
difficult to define complex (grasses, magnolias)
Horses were once much smaller, now they are very large
The rate of adaptation and speciation is typically
slower than rate of environmental change (but not always…)
development of similar trait in related but distinct species descending from a common ancestor
parallel evolution
Development of similar morphological and physiological traits of very different species (different taxonomy) living in geographically separate regions.
convergent evolution
Two species evolve traits tied to their interactions:
coevolution
“arms race” : Mollusks and snails form harder and harder shells to prevent being cracked and eaten by crabs and fish, in turn, the predators evolve larger and stronger claws or jaws for eating the mollusks
. Predator / Prey and or Parasite / Host relationships:
Plants and their pollinators
Symbiotic or mutualistic relationships
Brood parasites: Cowbird eggs mimic other species, the cowbird abandoned the egg and young to be feed by other species
competitive species
Biological Diversity of Species on Earth
biodiversity
biodiversity
richness, quantity of individuals, genetic diversity, habitat and ecosystem diversity
energy: earth is a
closed system
ecosytems are
semi closed systems, cyclic transfers of energy
Make energy from raw-organic sources such as light or inorganic chemical reactions Plants, algae, some bacteria
autotrophs
Get energy from
consumption
Animals, fungi,
bacteria
heterotrophs
autotrophs, photosynthesizers
producers
heterotrophs primary
herbivore
heterotrophs secondary
carnivores and omnivores
heterotrophs tertiary and quaternary
top carnivores, omnivores
energy from birds and mamma;s
3%
energy from fish
10%
energy from insects
39%
how much energy from lower level is passed on
10%
Total number of consumers any ecosystem can support is
limited by
the number of producers
autotrophs are primarily along the coasts, therefore
marine primary consumers are also along the coast
One organism consumes another
Presence or absence of prey can control distribution and
population of predator
Presence or absence of predator can control distribution
and population of prey
predation
selective predation
Stenophagus:
non selective predation
euryphagus
Two or more organisms with the same resource
requirements competing for the same resource
competition
interaction between individuals of two or
more different species in which the growth and/or fertility
is decreased and the mortality is increased for both
species, within community competition
interspecific
interaction between two or more
individuals of the same species in which the growth
and/or fertility is decreased and the mortality is increased
within that species, within population competition
intraspecific
no direct contact or interaction
Two species of birds that eat the same prey
resource exploitation
intraspecific is a common factor of
sympatric speciation
direct physical interaction or chemical reaction
One organism directly inhibits its competition
interference
physically limits establishment in an area - animals
aggression
when an organisms exudes a chemical that is
harmful to another organisms - plants
allelopathy
Close association between two species that generally
develops through co-evolution
symbiosis
interaction that benefits both species involved
mutualism
Benefits one species with no impact on other species
commensualism
One species benefits at the expense of the other
parasitism
One species evolves the appearance or behavior of
another species
mimicry
one poisonous/unpalatable species mimics another
poisonous/unpalatable species- both benefit from this mimicry
and they may or may not be closely related species
mullerian mimicry
palatable species mimics an unpalatable species
batesian mimicry
Organisms that influence the whole
composition of ecosystems by controlling
the population sizes of prey and/or
competing species
keystone species
Dating materials and surfaces
Ice cores
Glaciations and responses to deglaciation
Paylnology and Dendrochronology
geophysical tools for reconstructing climate
longest term changes
Unstable elements, measure decay of half life
Earth’s age 4.6 billion years
rADIOACTIVE MATERIAL DATING
mid-long term changes
Exposure at surface ~ 200k years ago
cosmogenic dating
-200k years
materials with low calcium, uranium, thorium
optically stimulated luminescence
pleistocen-holocene
Measure “recent” ages/dates ~ last 50k yrs
Organic remains
14C half life = ~5,700 years
radiocarbon dating
Bubbles trapped in ice as snow is
compacted, air is released and gas
contents are measured (ex: Oxygen
isotopes)
ice cores
greenland ice vs antarctic ice
100k vs 400k
extended period of cold
temperatures that includes one or more
glacial and interglacial periods
ice ages
Extent of Last Glacial
Maximum (LGM) in North
America, Europe, Russia,
and Asia
20k years ago
Shifts in extent and distribution of forest and deserts Warmer air holds more moisture and produces more precip
climate change sand biota
Biological Tools for
measuring climate and biota
change
palynology
packrat middens
dendrochronology and other dendro sciences
Study of fossil pollen and spore
analysis, often from sediment cores
palynology
palynology biological reconstructions
Pollen disperses and settles on soil, in
lakes, oceans, peatlands, etc.
Soils cores and pollen record can be used
to reconstruct biotic distributions
Up to 40,000 years biological and
climate history of fossilized “garbage”
Pollen, leaves, seeds, bones and other animal
parts, etc.
packrat and ringtail cat middens
Tree ring analysis Date time when rings form Annual cambium, 1 ring = 1 year Conifers 1,000 – 4,000 yrs. Infer temperature, moisture, disturbances
dendrochronology
measure climate fluctuations
dendroclimatology
fire occurence
pyrodendrochronology
measure geomorphic processes
dendrogeomorphology
Isolated patches for studying ecosystem dynamics
Population and community level interactions
Unique adaptations and evolutionary changes to
specialized niches
Islands are, in a sense, natural laboratories!
significance of island biogeography
islands can be
usual islands, ponds, mountain peaks, natural habitats surrounded by altered land uses
Species on islands are similar to that of the closest mainland
areas, often subset of the total species pool
Groups of islands in close proximity will contain similar subsets
of species
insular communities
Species found nowhere else – species which evolved on the island
More isolated islands support greater number of endemics
endemics
Correlation between island size and species richness:
Larger islands support greater species richness than
smaller islands
species area relationship
Islands nearer to the mainland receive greater number
of immigrants than islands farther from the mainland
Species richness decreases with isolation
species isolation relationship
Theory that there is a nearly consistent relationship, between species richness, island size, and island isolation, changes in species relationships
species turnover
STETIB: immigration is initially
high and then decreases
STETIB: extinctions are initially
low and then increase over time
STETIB: consistent exchange between
immigration and extinction which maintains equilibrium of species richness
exceptions to ETIB: highly transient species
Move very easily from mainland to island
Birds, insects, hydrochores and consistent currents
exceptions to ETIB: small island effect
there may be a threshold
size for an island before this relationship holds…
Islands can be so small there is minimal change in
species immigration and extinction
Species diversity and population density remain low
and stable
Minimal habitat diversity and niches are all filled
exceptions to ETIB: rescue effect
Islands near mainland may have significantly lower
extinction rates and thus lower turnover rates
Small populations are rescued from extinction by the
continued arrival of immigrants from the same species, i.e.
struggling populations are periodically replenished from
source group of insular communities on the mainland
exceptions to ETIB: target area effect
Larger islands are larger targets, even when isolated
Island forms often evolve a huge body size compared
to mainland relatives. Mostly a function of lack of predation
gigantism
Limited food sources, esp. for grazers (primary consumers), may
restrict size, Lagomorphs (rabbits and hares), and artiodactyls (deer, hippos,
and other even-toed ungulates)
dwarfism
y loss or reduction of
wings. It has been seen in huge numbers of both insects and birds
on most island groups.
flightlessness
most known extinctions since 1600 have been
on islands
