Terms in this set (115)
Long-term average of weather patterns in a particular area
How is climate determined across the globe?
-global patterns of wind and ocean currents
How are air currents caused?
The rise of warm air and descent of cold air, creating winds. High temperatures warm air near the equator and warm air has low density so it rises. Air rises to the poles and then becomes more dense and falls back down.
What causes ocean currents?
Winds drive the circulation of ocean surface water. Transports more heat towards the poles and creates different climates along similar latitudes.
How does topography affect air current/temperature?
Air rises over the mountain, cools, and releases its moisture as rain. Once over the mountain, the air descends, warming and taking up moisture.
What causes solar radiation?
The latitudinal difference in incoming solar energy density causes warmer areas around the equator and cooler near the poles.
How do animals maintain homeostasis in cold environments?
-move to areas that are warmer...sunlight
-thicker fat layers
-plants go dormant(no growth)
-animals reproduce when plants grow so they have enough resources to survive.
How do animals maintain homeostasis in hot environments?
-seek shade/cool areas
-long ears/extremities to dissipate heat.
How do animals maintain homeostasis in dry environments?
-in plants, stromata prevent water loss
-concentrated urine to conserve water (renal system)
How do animals maintain homeostasis in wet environments?
animals in aquatic environments release ammonia as their nitrogenous waste to maintain homeostasis
Tropical Rainforest Conditions
-Precipitation: a lot
-Temp: warm, on equator
-Day Length: dry & wet season, day length basically the same
-Sunlight: remains the same all day
-Precipitation: very little, dry
-Temp: from below freezing to 120
-Day Length: cold in winter and hot in the summer
-Sunlight: changes seasonally, more than tropical rain forests
Deciduous Forest Conditions
-Precipitation: 30-60 inches per year
-Temp: below freezing to hot and humid
-Day Length: seasonal changes
-Sunlight: more in summer, less in winter
-Precipitation: dry zone
-Temp: very cold
-Day Length: winter is almost completely dark
-Sunlight: can vary, sometimes doesn't appear or disappear.
-Primary producers: autotrophs that fix CO2 into organic carbon
-Primary consumers: heterotrophs that feed on primary producers
-Secondary consumers: heterotrophs that feed on primary consumers
-Decomposers: largely fungi and bacteria in soil that feed on organic detritus
-Comes from atmosphere and is fixed by soil-dwelling bacteria, making it accessible to plants and other soil organisms
-Builds Nucleic acids and amino acids
-Mostly present in rocks and is released when they are weathered
-Primary producers (plants) fix phosphate and then phosphorus is transferred through the food web by consumers and decomposers
-Creates ATP, nucleic acids, and phospholipids
How do carbon and nitrogen become fixed in the environment, making it accessible to other organisms within the food web?
-Carbon: autotrophs fix into organic carbon
-Nitrogen: fixed by soil-dwelling bacteria
How is nitrogen returned to either the atmosphere or soil?
digest it after consumption and then excrete it as waste (nitrogenous waste)
What is eutrophication?
-When nitrogen and phosphate get flushed into lakes and rivers after it rains, it's not a part of the soil it's just on top (can run off easily
-Nutrients allow algae to grow quickly, algal blooms
-Algal blooms block sunlight to underwater plants, decreasing dissolved oxygen
-Most aquatic animals and plants end up dying from lack of oxygen or light
How do wetlands decrease eutrophication?
-trap excess nutrients, pollutions
-reduce amount of runoff
What is evolution?
Change in the genetic structure of a population over time. ("descent with modifications over time in a population")
What are the three key elements of evolution?
-descent over time
-genetic modifications across generations
-natural and unpredictable
What is a population?
A group of individuals, that belong to the same species living in the same area and interact/interbreed with one another.
What is a species?
Individuals with similar characteristics that can produce fertile offspring. There can be multiple populations of the same species.
___________ changes, not ________________
What is microevolution?
-changes in a populations allele frequencies across generations
-shorter time scales
What is Macroevolution?
-Longer and can lead to bigger changes
4 Mechanisms of evolution?
Natural selection, genetic drift, migration/gene flow, and mutations.
What is natural selection?
-nonrandom: certain traits give an individual higher fitness.
-Must be a variation of traits within a population
-Variation must be heritable
-Differential reproductive success
-Individuals with certain traits produce more offspring that survive to reproduce and have a higher fitness level which increases the prevalence of that trait in the population over time
What is mutation(mechanism of evolution)?
-random change in the nucleotide sequence of either DNA or RNA
-random and rare, can be good bad or neutral
-Most are neutral and are in non-coding regions of the genome
-Within the coding region
-Most are harmful, some no effect, some benefit
What is migration/gene flow?
-change in genetic composition of a population due to the movement of individuals from one population to another established population
-The genetic composition of the migration individual is random
-With gene flow populations are connected
-Speciation has no gene flow, migration has stopped
What is genetic drift?
-Random fluctuations of alleles in a population
-Random mortality (wrong place wrong time, ex. natural disaster)
-Founder events: subset of the population leave their home and establish new population
-Small populations are more likely to experience genetic drift
-Human population will grow until not enough resources
-Births should be controlled or famine and starvation are going to happen
-Earth's crust formed through small changes over vast periods of time
-Darwin saw evidence on his voyage that supported Lyell's theory
-earthquakes, volcanoes, fossils of marine organisms on mountains
What are the 3 conditions required for natural selection to occur?
-Must be a variation of traits within a population
-Variation must be heritable
-Differential reproductive success
What are the biotic selection pressures?
Food, shelter, water, mate, predators, disease
What are the abiotic selection pressures?
Biome, day length/seasonality, weather patterns (rain and temp)
What are the five characteristics necessary for a population to be in HWE?
-No natural selection
-Random mating only, no inbreeding
-Large population size
What is the null hypothesis for HWE?
If populations are in Hardy-Weinberg Equilibrium, then evolution is not occurring. The null hypothesis is the population is not evolving.
What is the biological species concept?
species are groups of actually/potentially interbreeding populations that are reproductively isolated from other groups.
What are the limitations of the biological species concept?
-extinct species, fossilized remains
What are morphospecies?
members of the same species have similar morphological (structural) and genetic characteristics
What are ecological species?
Two organisms are considered different species, if they occupy different niches.
What are phylogenetic species?
members of the same species are descendants of a single common ancestor
If two organisms occupy the same niche are they the same species?
divergence of 2 separate species when the populations become reproductively isolated and genetically distinct
What is a pre-zygotic barrier?
Barrier that prevents a zygote from forming (no fertilization of gametes)
What is a post-zygotic barrier?
fertilization occurs, but the offspring either do not survive to maturity or are sterile.
-in-viability, sterility, genetic incompatibility.
What is allopatric speciation?
populations separated by geographical barriers that prevents populations from interbreeding
What is sympatric speciation?
populations are in the same geographic location, but gene flow has stopped between populations
What is a proximate explanation?
Causation & development, the "how"
What is an ultimate explanation?
Adaptive function & evolutionary history, the "why"
What is an innate behavior?
Instinctive behaviors, genetically derived & programmed. Influenced by the environment.
What is a learned behavior?
Behaviors as a result of experience.
What is non-associative learning?
learning that involves changes in the magnitude of responses to a stimulus, habituation & sensitization
What is associative learning?
learning that certain events occur together. classical conditioning & operant conditioning
What is habituation?
A decrease in response to a stimulus after repeated presentations. Aka squirrels
What is sensitization?
an increase in behavioral response after exposure to a stimulus, aka alarm clocks
What is classical conditioning?
neutral stimulus that results in a reward, causes a behavior
What is operant conditioning?
Learning with positive and negative reinforcement
What is visual communication?
Communication of a message or idea through the visual display of information instead of verbal
What is auditory communication?
a very rapid kind of communication that works at a distance both during the day and at night.
What is chemical communication?
Occurs through chemicals called pheromones
What is mechanical communication?
Occurs between fish, they send signals through the water through their body movements.
What is communication?
The transfer of information between two individuals, the sender and the receiver
What do circadian clocks do?
regulate daily rhythms like feeding, sleeping, hormone production, and body core temp.
What do lunar clocks do?
Control seacoast species that live where lunar tides are important.
What do annual clocks do?
Help to detect yearly and seasonal changes, for things like migration.
What is altruism?
An act of self-service that helps another
What is reciprocal altruism?
Individuals help eachother assuming it will be reciprocated
What is kin selection?
Helping/help of close relatives/kin.
What are fixed action patterns?
A sequence of behaviors that once triggered, are followed through to completion.
What is ecology?
The study of the interactions of organisms to their environment and other organisms.
How do scientists study and measure populations?
measure population size, range, and density
What are the different types of distribution patterns?
clumped, uniform, and random
What are the two types of population growth?
exponential and logistic
What are the density dependent limiting factors?
competition, predation, parasitism, disease
What are the density independent limiting factors?
climate, natural disasters or extreme weather events
What is a type I survivorship curve?
low mortality rate for young, high mortality rate for old.
What is a type II survivorship curve?
constant mortality rate
What is a type III survivorship curve?
high mortality for younger individuals, sharp decrease in mortality for adults
What is an r-strategist?
a species that produces lots of tiny offspring and gives little parental care. Type III survivorship
What is a K strategist?
a species that produces fewer large offspring with lots of parental care. Type I survivorship
What are metapopulations?
Large population made up of smaller populations that are linked by movement between small populations.
How do colonization and extinction rates change with size?
Larger = down extinction, up colonization
Smaller = up extinction, down colonization
How do colonization rates change with distance?
Farther = down colonization
Nearer = up colonization
What is a niche?
The role a species plays in a community & the habitat needed for it to survive and reproduce.
What is a fundamental niche?
the full range of environmental conditions under which an organism can live theoretically
What is a realized niche?
The range of resources that a species actually uses
What are the 4 interactions that may be restricting a species niche?
competition, predation, mutualism, and commensalism
What is competition?
the struggle between organisms to survive as they attempt to use the same limited resources
What is predation?
One individual benefits, the other is harmed
What is mutualism?
Both individuals benefit
What is Commensalism?
one species benefits and the other is unaffected
What is competitive exclusion?
One species wins and the other loses and becomes "locally extinct"
What is resource partitioning?
Each species uses different types of resources in a habitat
What are primary producers?
plants and other photosynthetic organisms
What are primary consumers?
What are secondary consumers?
omnivores and predators of herbivores
What are tertiary consumers?
What is sucession?
What is primary succession?
succession that occurs on surfaces where no soil exists
What is secondary succession?
Process of a species replacing eachother in an area, after a disturbance event with soil still present
What is the relationship between greenhouse gases and global temperature?
Greenhouse gases absorb heat and reflect it back on earth's surface
What is biodiversity?
The number of living organisms within an area or ecosystem
What areas are in the most danger of extinction?
What are the conservation priorities and the role of metapopulation dynamics?
1. biodiversity hotspots
2. threatened and endangered species
3. protecting and restoring ecosystems
What are ecosystem services?
Benefits that ecosystems provide for humans
What are the benefits of ecosystem focused conservation?
1. protecting natural habitat
2. minimize or eliminate overexploitation of protected species
3. buffer against invasive species
4. help conserve all species within the ecosystem
What is sustainable management?
Managing and using a natural resources in a way that they remain for future generations
Where geographically is species diversity at its highest?
Tropical rain forest
Where geographically is species diversity at its lowest?
What is a coevolutionary arms race?
Adaptations and counter-adaptations that occur over time in +/- species interactions.
What is an age pyramid?
A visual represntation of population growth - goes from triangular to rectangular when population growth stabilitizes.