Bio 2 Exam 4 Flashcards
What is ecology?
Study of interactions among organisms and their environment
What is a biotic interaction?
Interactions among living things
What are abiotic interactions?
Between organisms and their nonliving environment
What do biotic and abiotic interactions govern?
The number of species in and area and their population densities
What are the scales of ecology?
starts at organismal ecology, population ecology, community ecology, and ends at ecosystems ecology
What does hypothesis testing involve?
- observations
- hypothesis formation
- experimentation
- data analysis
- acceptance or rejection of hypothesis
What do graphs imply in hypothesis testing?
Imply correlation or meaningful relationship between 2 variables. CORRELATION DOES NOT MEAN CAUSATION
What is the impact of the environment?
Both geographic distribution pattern and abundance are limited by physical features of the environment
What are five important physical features of the environment?
- temperature
- wind
- water and light availability
- salinity
- pH
What is the impact of temperature?
Most important factor in the distribution of organisms (effects biological processes inability of most organisms to regulate body temperature precisely)
What is an example of the impact of temperature in the environment?
Coral reef organisms abundant only in warm water due to effects of temp on coral distribution.
— shell formation and coral deposition are accelerated at high temperatures but are suppressed in cold water
What is the second example of the impact of temperature on the environment?
Frost is the most important factor limiting geographic distribution of tropical and subtropical plants (ex. cactus distribution limited to places where temp does not go below freezing for more than one night)
What are two examples of the impact of high temperatues?
- corals expel symbiotic algae when temperatures are too high (coral bleaching)
- giant sequoias depend on fire to enhance seed release and clear out completing vegetation
What is the greenhouse effect?
Solar radiation passes through the atmosphere and heats the Earth’s surface —-> energy radiated from the Earth back into atmosphere —-> atmospheric gases (CO2, methane, water vapor) absorb the energy and reradiate to the Earth’s surface increasing temperature
What is global warming?
All greenhouse gases have increased in atmospheric concentrations since industrial times due to human activities
–As a result, anticipated changes in global climate will occur too rapidly for normal evolutionary processes to compensate
What is an example of global warming?
Climatic zones may shift faster than trees can migrate via seed dispersal resulting in extinction
What is the impact of pH?
- normal rainwater = pH of 5.6
- most plants grow best at pH 6.5 when nutrients are most available (pH less than 5.2 prevents nitrifying bacteria from working)
- chalk and limestone areas have a richer flora than acidic soils
- numbers of fish and other species decrease in acidic waters
What is acid rain?
- pH less than 5.6
- results from the burning fossil fuels containing sulfur dioxide and nitrogen oxide
What is behavioral ecology?
Studies how behavior contributes to the differential survival and reproduction of organisms
What is a fixed action pattern (FAP’s)?
Innate (instinctual) or genetically programmed behavior. Once initiated, will continue until completed
–ex. egg-rolling response in geese (improves fitness and increases survival of young)
What is a critical period?
Time when many animals develop species-specific patterns of behavior
–ex. imprinting - goslings follow the first moving thing as “mother”
What is habituation?
Simplest form of learning (non-associative learning where organism ignores repeated stimulus-decrease in response to stimulus due to repetition)
What is associative learning?
Association develops between stimulus and response
What are the two main types of associative learning?
- Classical conditioning
- Operant conditioning
What is classical conditioning?
Involuntary response becomes associated positively or negatively with a stimulus that did not originally elicit the response (ex. Pavlov’s dog salivates when a bell rings)
What is operant conditioning?
Animals behavior reinforced by a consequence (reward or punishment, also called trial-and-error learning)
—ex. birds will learn to avoid toxic butterflies
What is cognitive learning?
Ability to solve problems with conscious thought and without direct environment feedback
–ex. chimp. stacking boxes to reach bananas
–ex. ravens retrieving meat by pulling on a string
What is behavior often a mix of?
It is a mix of innate and learned ( ex. birds are genetically programmed to learn but they will sing the correct song only of correct song is heard)
What is population ecology?
Study of what factors affect population size and how these factors change over space and time
What is a population?
A group of interbreeding individuals occupying the same habitat at the same time
What is density?
Number of organisms in a given unit area. Population growth affects population density (ex. knowledge on density and growth can help make decisions about species management)
What are the three dispersion patterns?
- clumped (most common)
- uniform
- random (rarest)
What is a clumped dispersion pattern?
Resources tend to be clustered in nature. Social behavior may promote this pattern
What is a uniform dispersion pattern?
Competition may cause this pattern. May also result from social interactions (beavers have a fairly uniform rate of death over the life span)
What is a random dispersion pattern?
Resources are rarely randomly spaced may occur where resources are common and abundant
What are survivorship curves?
Plots numbers of surviving individuals at each age
What are the two life history strategies?
- r-selected species
- k-selected species
What are r-selected species?
High rate of per capita population growth, but poor competitive ability (weeds)
What are K-selected species?
More or less stable populations adapted to exist at or near carrying capacity
What is human population growth?
In 2006, the worlds population was estimated to be increasing at the rate of 146 people every minute
In what two ways can human populations exist at equilibrium densities?
- High birth and high death rates
- Low birth and low death rates
What are high birth and high death rates?
Before 1750, this was often the case, with high birth rates offset by deaths from wars, famines, and epidemics
What is low birth and low death rates?
- In Europe, beginning in the 18th century, better health and living conditions reduced the death rate
- eventually, social changes such as increasing education for women and marriage at a later age reduced the birth rate
What is a population pyramid?
Relative numbers of individuals in each defined age group –> helps predict future population growth
What is the Total Fertility Rate (TFR)?
Average number of live births a women has during her lifetime (2.3 = zero population growth)
What is carrying capacity?
The maximum population size of the species that the environment can sustain indefinitely, given the food, habitat, water and other necessities available in the environment