Classification
Early Systems

Aristotle’s classification
• Plant/animal?
– Water/air dweller?

Common name confusion : robin, fir
tree, jellyfish
Linneaus

1700’s

Hierarchy based on morphology

7 original levels

Domain (newest level)
• Kingdom
– Phylum (animal) Division (plant)
• Class
– Order
–
–
–
Family
Genus
species
Classification Hierarchy of Organisms
Binomial Nomenclature

Species names has 2 parts: genus and
species = scientific name

Genus is capitalized species is not

Italicize or underline

Name may be descriptive or “in honor of”
Systematics

Taxonomy: naming and
grouping of organisms

Systematics – based on
natural relationships
including
• Embryology,
• Chromosomes
• DNA/RNA

Gets “revised” as new
info is learned

Cladistics
Based on certain features “shared derived
characters” I.e. feathers within birds (unique)

Birds probably had a common ancestor
because they all have feathers
Phylogenetic Diagram of major groups
of organisms
3 Domain System

Based on analyses of rRNA

Bacteria – (Eubacteria)

Archae – (Archaebacteria)

Eukarya (protists, fungi, plants animals)
Modern Classification
Modern Classification
6
Kingdoms w/in 3 domains
• Archaebacteria
• Eubacteria
• Protista
• Fungi
• Plantae
• Animalia
ECOLOGY- Ch 18 Notes
ECOLOGY
•
•
•
The study of living organisms and their
interaction with the environment
Interdependence: Everything is
connected!!!!
Make Models to help
understand/explain
Making an Ecosystem Model
Levels of Organization
•
Biosphere - Earth & its
atmosphere that supports life
• Ecosystem - organisms & their
environment (living & non-living in
an area)
• Community - interacting organisms, all
living orgs.
• Population - members of same species in
one place
• Organism - adaptations of individuals
Levels of Organization
Ecology Consists Of:
•
BIOTIC Factors -
living things
•
ABIOTIC Factors -
non living (pH, temp.
sunlight, soil type)
Responses to Environmental
Change
•
•
Acclimation - occurs within an
individuals lifetime, you are able
to function normally
Control Internal Condition
• Conformer - body temp rises & falls
w/ environment (ex. Fish)
• Regulator - use energy to control
your insides (mammals)
•
Responses to Environmental
Change
Escape
• hide underground if hot
• dormant for long periods of time
• migrate - move to better climate
Tolerance Curve
•
•
Level of change an organism can
handle
Range of an organism may be
determined by this
Niche’s
•
The role of the species in the
environment
• Fundamental - potential range of
conditions & resources the
species can tolerate
• Realized - range of conditions &
resources the species actually
uses. Usually narrower than
fundamental
Earthworm Niche
•
•
Niche Differences
Generalists - Broad range of
conditions & variety of resources
(cockroach)
Specialists - very narrow niche,
feeds on specific food (koala)
Energy Transfer
•
Involves
• Producer
• Consumer
• Energy Flow
Producers
•
•
•
Autotrophs - include plants,
some protists & bacteria
Photosynthetic - use sunlight as
energy source
Chemosynthetic - use inorganic
molecules as energy source
(hydrogen sulfide)
Consumers
•
•
•
•
•
Cannot make their own food, must eat
others, heterotrophs
Herbivore: producer eater
Carnivore: consumer eater
Omnivore: eat producer & consumer
Detritivore: Feed on “garbage,” dead
stuff, animal waste – has a face
• Decomposer - cause decay by breaking
down tissue & waste – no face
Who Eats Whom?
•
Food Chains (simple)
•
Food Webs
(complex)
•
Trophic Levels:
Energy flows from
one trophic level to
another
Antarctic Food Chain
Antarctic Food Web
•
•
Trophic Levels
Autotrophs: plants = 1st trophic level
Heterotrophs: Cannot make their own
food
• Herbivores: 2nd trophic level
• Carnivores: 3rd trophic level & up
• Omnivores: Above 1st Trophic level
What Happens as Energy Moves
Through a Food Chain?
•
Organisms are not 100%
efficient
– about 10% of the energy at
one level makes it to the next
level (90% lost)
The 10% Rule & Trophic Levels
What Happens as Energy Moves
Through a Food Chain?
•
Energy is lost, by the
organisms basic needs and
heat
What Happens as Energy Moves
Through a Food Chain?
Implications
•
•
Usually no more than 3-4
levels in a food chain
Fewer and fewer organisms in
the food chain as you go up
Why are there more
grasshoppers than grizzly bears?
Productivity
•
•
•
How “productive” in making
carbohydrates in the ecosystem
Carbs used for - cellular
respiration, maintenance, growth,
reproduction
biomass - amount of organic
material produced in an
ecosystem---producers add
biomass
Primary Productivity
•
•
Gross Pri. Prod. (GPP) - rate
producers capture energy….is
total amount
Net Pri. Prod. (NPP) - rate
biomass accumulates
(carbohydrates used for
maintenance don’t result in
biomass)….is amount left over
after deductions made
Net Primary Productivity
•
•
•
•
Only biomass is available to
other organisms
2
expressed as (kcal/m /yr) or
g/m2/yr)
NPP = GPP - respiration rate in
producers
Varies among ecosystems….
is
biomass greater in tropical rain forest or desert?
Biogeochemical cycles
•Nutrients are essential to the
success of ecosystems
•Nutrients cycle between the
biotic and abiotic components
of the ecosystem
•Removal of trees = higher rate
of nutrient and water loss
•CHNOPS are most important!
Water Cycle= Hydrologic
•More water = more diversity
•Plants are integral - take up water, and
it evaporates into atmosphere through
their leaves (transpiration)
•Evaporation from oceans & lakes
•Involves precipitation, reservoirs of
groundwater, vapor
•No plants = lose water to runoff
Water Cycle
Carbon Cycle
•Carbon is in carbon dioxide in air gets there by cellular respiration
and burning fossil fuels
•Taken out of air by photosynthesis
•Living organisms are made of C,
must get it by eating organisms
•Cutting forests = increase CO2
levels - global warming
Carbon Cycle
Nitrogen Cycle
•Needed for proteins and
nucleic acids
•Nitrogen gas makes up ~78%
of atmosphere but cannot be
taken in directly from air by
animals; need to be assimilated
by plants first
Nitrogen Cycle
5 Steps to memorize
Nitrogen fixation: take N2 gas out of air and convert into
ammonia or nitrates (by bacteria & lightning)
Nitrification: ammonium (NH4+)  nitrate (NO3) by
bacteria to be taken up by plants (soil bacteria oxidize)
Assimilation: plants take up ammonia, ammonium and
nitrate ions through roots (animals can then eat)
Ammonification: dead organisms & waste (through
urine/dung) contain Nitrogen  ammonia & ammonium ions
(by decomposer bacteria) for plants
Denitrification: N2 released back into atmosphere (by
bacteria)
Plants use nitrates to form AA, animals get nitrogen
by eating plants
Nitrogen Cycle
Phosphorus Cycle
•phosphorus moves from phosphate
deposited in rock, to the soil, to
living organisms, and finally to the
ocean
Populations-Ch 19
Properties of Populations
•
Size - can be counted or estimated
•
Density - How crowded they are U.S. =
30 people/Km2
•
Topics:
• Dispersion
• Growth rate
• Age structure
• Survivorship curves
Dispersion
•
Clumped
•
Random
•
Uniform/Even
Age Structure
•
% of individuals among
different ages
Patterns of Mortality
•
Shown in survivorship curves
•
Type I - young survive
•
Type II - many die young
•
Type III - most die young
Measuring Populations
•
Demographers: study population dynamics
•
Growth Rate: Amount a population changes
in a given time
•
Birth, death, immigration, emigration
determine growth rate
•
Growth rate = B.R. - D.R.
Calculating Populations
•
Done per capita (person)
•
Growth rate X current popl. Size =
yearly increase
•
+ = growing, - = decreasing
Exponential Growth
•
Rapid increase after a few
generations, the bigger it gets, the
faster it increases
•
“J shaped curve”
•
B & D rate are constant
•
Populations cannot grow
indefinitely like this because of
limiting resources
Two Growth Models
Logistic Growth
•
Similar to exponential, but
includes carrying capacity (max
number = K)
•
Birth rate falls & death rate
climbs as popl. grows
•
Carrying capacity can fluctuate
•
S-shaped curve
Population Regulation
•
Density-independent: flood, fire, weather doesn’t matter how many individuals there
are
•
Density-dependent: resource limitation,
food, nesting site, brought on by increased
population
Population Fluctuation
•
More prey = more predators
•
Less prey = less predators
•
Wolf and moose population might
cycle together
Small Populations
•
Inbreeding is likely
•
Fewer offspring, more susceptible to
disease, shorter life span, decreased
genetic variability = bottleneck effect!
The human popl. explosion
•
Long ago were hunter-gatherer’s, small
populations, high mortality
•
Agricultural Revolution (10,000 years ago):
Better food supply
•
Decrease death rate: sanitation, food,
economics
Demographic Transition
•
How populations change as a country
industrializes
The human popl. explosion
History of Human Popl.
Growth
•
Began ~1650
•
After WWII fastest growth rate ever b/c
of sanitation & medical care
•
Today: faster in developing rather than
developed countries
Developed Countries
•
20 % of world popl.
•
U.S., Japan, Germany,
France, Russia, Canada,
Australia
•
Better educated, healthier,
longer living
•
Growth rate is less than 0.01
Developing Countries
•
80 % of world popl.
•
Most of Asia, Central
America, South America,
Africa
•
Poorer, less educated
•
Growth rate is more than
0.02