Test 1 Slide Questions Flashcards
Scientific Method
Observations, Questions, Hypothesis, predictions, Test, Results
In manipulative (controlled) experiments
the researcher actively chooses and manipulates the independent variable.
These are not always possible, such as in the case of global climate change.
Natural experiments
compare how different variables are expressed in naturally occurring, but different, contexts.
The independent variable varies naturally, and scientists search for correlation, or statistical association, between variables.
Scientific Literature
Sources of scientific information:
o Peer-reviewed – double blind reviewed by experts
o Gray literature – technical documents written by
scientist/experts
o Popular press
o Primary v. secondary sources
Peer-Reviewed
Double Blind Reviewed by experts
Gray Literature
Technical documents written by scientists/ experts
Ecocentrism
judges actions based on their effects on ecological systems, which contain both living and nonliving elements and relationships between them.
Biocentrism
ascribes inherent value to living things.
Anthropocentrism
ascribes value to nature only to the extent that it benefits humans in some way
John Muir
promoted a preservation ethic, believing that the environment should be protected in a pristine, unaltered state.
o “Everybody needs beauty as well as bread, Places to play in and pray in, where
nature may heal and give strength”
Gifford Pinochet
promoted the conservation ethic, which holds that people should put natural resources to use but have a responsibility to use them wisely.
o “…greatest good of the greatest number for the longest time…”
Aldo Leopold
was originally a forest manager who embraced the government policy of shooting predators to increase the population of deer and other game animals.
o “A thing is right when it tends to preserve the integrity, stability, and beauty of the
biotic community. It is wrong when it tends otherwise.”
Environmental justice
involves the fair and equitable treatment of all people with respect to environmental policy and practice, regardless of their income, race, or ethnicity.
o Poor people and ethnic minorities tend to be exposed to more pollution, hazards,
and environmental degradation than wealthier people.
Distributional equity
how resources/burdens are distributed
Procedural equity
who gets to participate in decision making
Recognition
which frameworks/points of view are recognized
feedback loop
A system’s output may serve as input back into the same system
negative feedback loop
results when the system moving in one direction acts as an input that causes the system to move in the opposite direction.
Positive Feedback loops
occur when increased output in a system leads to increased input, which further stimulates output.
Matter
All material in the universe that has mass and occupies space.
Elements
A fundamental type of matter; a chemical substance with a given set of properties, which cannot be broken down into substances with other properties. Chemists currently recognize 92 elements that occur in nature, as well as more than 20 others that have been artificially created.
Atom
The smallest component of an element that maintains the chemical properties of that element.
Isotope/Radioisotope
An “isotope” refers to any atom of a particular element with the same number of protons but a different number of neutrons, while a “radioisotope” is a specific type of isotope that is unstable and emits radiation due to its excess nuclear energy
Ions
An electrically charged atom or combination of atoms.
macromolecule
A very large molecule, such as a protein, nucleic acid, carbohydrate, or lipid.
DNA
A double-stranded nucleic acid composed of four nucleotides, each of which contains a sugar (deoxyribose), a phosphate group, and a nitrogenous base. DNA carries the hereditary information for living organisms and is responsible for passing traits from parents to offspring. Compare RNA.
Proteins
A macromolecule made up of long chains of amino acids.
Carbohydrates
An organic compound consisting of atoms of carbon, hydrogen, and oxygen.
Lipids
A class of chemical compounds that do not dissolve in water and are used in organisms for energy storage, for structural support, and as key components of cellular membranes.
PH scale
A measure of the concentration of hydrogen ions in a solution. The pH scale ranges from 0 to 14: A solution with a pH of 7 is neutral; solutions with a pH below 7 are acidic, and those with a pH higher than 7 are basic. Because the pH scale is logarithmic, each step on the scale represents a 10-fold difference in hydrogen ion concentration.
The overall process of photosynthesis can be summarized in this reaction:
6CO2 + 6H2O + light energy → C6H12O6 + 6O2
The overall reaction for cellular respiration is the exact opposite of photosynthesis:
6CO2 + 6H2O → C6H12O6 + 6O2
Energy
is the capacity to change the position, composition, or
temperature of matter.
Potential Energy
is the energy of position.
o For example, river water held behind a dam contains
potential energy.
Kinetic energy
is the energy of motion.
o River water rushing through a dam and downstream
contains kinetic energy.
Energy is able to be converted back and forth between these two forms.
The first law of thermo Dynamics
Energy can change from one form to another, but it cannot be created or destroyed.
second law of thermodynamics
The nature of energy tends to change from a more-ordered to a less-ordered state as it changes form.
Primary Production
The conversion of solar energy into chemical bonds in sugars
Gross primary production
The total chemical energy produced by autotrophs
net primary production
The energy that remains after respiration is used to generate biomass (leaves, stems, and
roots)
secondary production.
Energy used by consumers to generate
their own biomass
Water cycle
the continuous movement of water on, above, and within the Earth and its atmosphere
Carbon cycle
the process by which carbon atoms move between the Earth’s atmosphere, living organisms, ocean, and rocks and sediments
Nitrogen cycle
the repeating circularization of nitrogen through organic and inorganic materials.
Phosphorus Cycle
a biogeochemical cycle that describes the movement of phosphorus through the environment, including the lithosphere, hydrosphere, and biosphere
Evolution is driven by natural selection
a process that favors certain inherited characteristics over others, causing them to be passed on more frequently.
The idea of natural selection is based on three observations:
o Organisms face a constant struggle to survive and reproduce.
o Organisms tend to produce more offspring than can survive to maturity.
o Individuals of a species vary in their attributes.
Biodiversity or biological diversity
refers to the variety of life across all levels.
o Species, genes, populations, and communities.
speciation
The process by which new species are generated is termed
Allopatric speciation
occurs when populations become
physically separated over a geographic distance
The Sixth Mass Extinction Is Upon Us?
Many biologists have concluded that the Earth is currently entering its sixth mass extinction event.
Causes stem from human population growth
Habitat Destruction
Invasive Species
Pollution
Hunting and Fishing
Climate Change
Habitat
Each organism has a relationship with its habitat, the environment in which it lives.
o Rock, soil, leaf litter, plant life, etc.
o Depending on the species, a habitat may be a square meter of soil or many miles of land.
Species Area Relationship
S=cA^z
S = Number of Species
c = Constant
A = habitat Area
Z = Slope of curve when plotted on log Scale
Niche
An organism’s role in its community. Includes resource use and interaction with other organisms
o Generalist v. Specialist
Population density
describes the number of individuals per unit area.
limiting factors
Eventually, every population is constrained by
physical, chemical, and biological limiting factors in
the environment.
The actual population growth rate includes the effects of emigration
and immigration:
(birth rate − death rate) + (immigration rate − emigration rate)
Rates may be expressed per 1000 individuals per year. These can be used in the formula.
Population distribution
describes the spatial arrangement of organisms within an area.
o Random shows no particular pattern.
o Uniform has individuals spaced evenly.
o Clumped occurs when individuals concentrate in certain areas.
Growth rates may be expressed as percentages:
population growth rate × 100%
carrying capacity
the maximum population size of a species that an
environment can sustain.
logistic growth
Population growth slows as it reaches the carrying capacity. This produces an S-shaped curve
trophic level
Species in a community are given a rank within the feeding hierarchy
Ecologists organize species interactions into several main categories
Competition − −
Predation, parasitism, herbivory + −
Mutualism + +
“+” denotes a positive effect; “−” denotes a negative effect.
resource partitioning
Over many generations, natural selection may favor resource partitioning, where individuals use shared resources in different ways.
Producers
use photosynthesis or chemosynthesis to make their own sugars
Primary consumers
consume producers
Secondary consumers
prey on primary consumers
Tertiary consumers
prey on secondary consumers
Detritivores
scavenge waste and dead bodies.
Decomposers
break down nonliving matter into smaller molecules.
o These play an especially important role in cycling nutrients back into soil for plants to use.
A trophic level will:
only have about 10% of the energy content,
organisms, and biomass compared to the level below it.
At each trophic level:
most of the energy input is either used for
maintenance or lost as heat
keystone species
A species that has an impact far greater than its abundance
Keystone species include:
Decomposers that recycle nutrients and replenish the
soil.
“Ecosystem engineers,” such as beavers and prairie dogs, who physically alter ecosystems.
Top predators, who control populations of lower trophic
level consumers, are often keystone species.
Primary succession
occurs when a disturbance removes all plant or soil life.
Lichens secrete acids that break down rock, beginning the process of soil formation.
Secondary succession
begins with a disturbance that alters the community but leaves the soil life intact.
o Farming, fires, storms, and landslides are examples.
Introduced species
are non-native arrivals to a community brought by people.
invasive species.
introduced species that thrive
Introduced species become invasive:
when limiting factors that normally regulate their population growth are absent.
o Lack of competition, predators, or parasites.
Climate Helps Determine Biomes
Temperature and precipitation exert the
greatest influence on which biome is found in
a given area.
Climate diagrams
also called climatographs, depict seasonal changes in temperature and precipitation and help to tell the story of a biome.
Deciduous forests
for example, are found at mid-latitudes and have relatively even precipitation throughout the year.
o Winters are frozen, causing the trees to drop their leaves.
An economy
is a social system that converts resources into
goods and services.
o Goods are material commodities.
o Services include work done for others.
Economics
is the study of how people use potentially scarce resources to provide goods and services that are in demand.
Economies receive
inputs from the environment, process them, and discharge outputs back into the environment.
o Traditionally economics overlooked these interactions.
The market moves toward an
equilibrium point, where supply equals demand.
Neoclassical economics
describes a conflict between buyers (who want a low price) and sellers (who want a high price).
o The compromise is the result of supply (the amount of product offered for sale at a given price) and demand (the amount of product people will buy at that
price).
Natural resources
ecosystem goods, include fresh water, trees that provide timber, and the energy from the sun, wind, water, and fossil fuels
Ecological services
include air and water purification, soil formation, climate regulation, pollination, and waste recycling.
Adam Smith
argued that self-interested economic behavior can benefit society, as long as it is controlled.
classical economics
where, under the right conditions, the marketplace will behave as if guided by an “invisible hand” to benefit society.
Externalities
additional costs or benefits not reflected in the price of a good or service. The presence of those externalities is what causes the market failures.
Market failure
occurs when positive outside forces (like ecosystem
services) and external costs are not considered.
In markets, ideally supply and demand:
balance each other out. A change in one side leads to corresponding changes in the other to maintain equilibrium. A market failure is anything that interferes with this balance.
Government intervention is intended to counteract market failure
o Taxes on harmful activities, like smoking.
o Laws and regulations to prevent long-term damaging behaviors.
o Economic incentives to promote conservation and
sustainability.
External costs/benefits
affect others besides the buyer and seller. Examples
include:
o Health impact
o Depletion of resources
o Aesthetic damage
o Financial loss
Tragedy of the Commons
Garrett Hardin theorized the Tragedy of the Commons as a particular type of Prisoner’s Dilemma.
o Tragedy of the Commons: If many people have unfettered access to a resource (e.g.
pasture, forests, fishery) they will tend to overuse it and make everyone worse off.
The pasture example
o Everyone has access to a commonly held pasture
o No rules about sustainable numbers for grazing
o Each herder benefits more from adding more animals than they lose from overgrazing
o The result: the pasture is overgrazed
