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66 Cards in this Set
- Front
- Back
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the study of geographic distribution and abundance of organisms that results from interactions between organisms and their environment
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Ecology
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an organism’s surroundings
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environment
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physical environment, like temperature, moisture, or day length.
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abiotic environment
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other living species
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biotic environment
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an applied science, based on applying ecological principles to solve specific problems, like reforestation or detoxification or recycling organic waste.
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Environmental Science
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is a political movement
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Environmentalism
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What determines the geographic distribution of a species?
What determines the abundance of individuals in a population? What maintains diversity of species within a community? |
Resources, intraspecific interactions (between same species), interspecific interactions (between different species), and abiotic factors
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how did Bald Eagles go extinct?
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DDT Poisoning and habitat loss
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when individuals aggregate in patches.
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Clumped Dispersion
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when individuals are evenly spaced.
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Uniform Dispersion
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the position of each individual is independent of the others
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Random Dispersion
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How does population size change over time?
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An essential feature of biological populations is the capacity to grow geometrically or exponentially.
examples 1. Fish Population growth 2. Money growth 3. Milk Going Sour by bacterial action |
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Live Population at a given generation
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Nt = btN0
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r = b - d
Where b is the birth rate per capita and d is the death rate per capita r > 0 means population is growing r < 0 means population is declining r = 0 means population size is stable |
Intrinsic Rate of Increase
(little r) |
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exponential growth?
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All populations can grow exponentially under ideal conditions
Exponential Growth: dN/dt=rN Rate of change in population equals birth rate – death rate multiplied by population size |
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when does exponential growth occur?
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when the growth rate of a mathematical function is PROPORTIONAL to the function's current value
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The number of individuals in a population that the resources of its environment can support
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Carrying Capacity (K)
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Growth, that slows steadily as the entity approaches its maximum size
dN/dt=rN K-N/K Population growth stops when N = K because at that point, K – N = 0, so (K – N)/K = 0, and thus dN/dt = 0. |
Logistic Growth
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birth rate exceed death rate
unlimited resources introduced spp. rebounding populations |
characteristics of exponential growth
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constrained by carrying capacity (K)
S-shaped curve K - not fixed varies over space / time can lead to population size fluctuations |
characteristics of Logistic Growth
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The way in which an organism partitions its time and energy among growth, maintenance, and reproduction
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Life History Strategy
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what does natural selection favor?
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Traits that maximize SURVIVAL and REPRODUCTION
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Decisions?
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when to begin reproducing
trade off between early reproduction & growth e.g., reproduce early and inefficiently? or wait? how often to reproduce reproduce every year? skip years? multiple times per year? how many offspring / reproductive event many offspring vs. fewer due to constraints: tend to be fewer better provisioned or more less provisioned |
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conflicting demands on time,energy, and nutrients
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use nutrients now, may not have them for next time
invest in one offspring, time spent can’t invest in other offspring |
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A species whose life history strategy allows for a high intrinsic rate of population increase
high growth rate / poor competitive abilities many seeds / good seed dispersal |
r-selected species
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A species whose life history strategy allows it to persist at or near the carrying capacity of its environment.
stable populations existing at or near carrying capacity competitive - out compete r-selected species in long run few seeds / poor dispersal |
K-selected species
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limitations on Population Growth?
dependent and independent factors |
Density-dependent factors
a factor with an effect on population size that changes in proportion to population density. 1.)Pathogens 2.)Predators 3.)Food supply Density-independent factors a factor with an effect on population size that acts independently of population density. 1.)Temperature 2.)Moisture |
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when two species each require the same limited resource. The availability of the resource to one species is negatively influenced by the presence of the other species.
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Competition
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When two species make similar demands
on a limited resource, then one or the other species will go extinct as a result of competition for the resource |
Gause's competitive Exclusion Principle
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each survives
indefinitely when reared alone |
Single species Populations
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In Intermediate Climates
each species won in at least some of the competition populations. The outcome of competition was not completely Predictable. |
Stochastic Outcome
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two-footed animal ex. birds, humans, primates.
use of hands better energetics ability to see body temperature regulation |
Biped
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four-footed animals ex.cattle, horse, cats, insects like praying mantis or reptiles like lizard
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Quadruped
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Convergent evolution from Homo Erectus into Homo Sapiens
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Multi-Regional Hypothesis
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Homo Sapiens evolved in Africa and spread throughout the World.
Genetic evidence supports this hypothesis |
Out of Africa Hypothesis
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Strong Genetic evidence that humans and chimps shared common ancestors?
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1. Morphology and fossils
2.Genetic Similarity 3. Genome arrangement |
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Are Humans currently under selection?
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YES
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is natural selection as strong as it once was ?
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NO
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How to describe an Ecological Population?
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gene frequencies (PA, Pa)
genotypic frequencies (GAA,GAa,Gaa) |
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geographic area where the species occurs
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Distribution
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Number of individuals per unit area
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Density
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Distribution of individuals of within a specific small region
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Dispersion
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individuals of the same species present in the same place at the same time
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Population
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the assemblage of populations of different species present in the same place at the same time
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Community
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the community of species present PLUS the abiotic environment(climate) with which they interact
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Ecosystem
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competition between members of the same species
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Intraspecific competition
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competition between members of the different species
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Interspecific competition
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indirect competition for the same resources
ex: food/lodging |
Resource competition
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interact directly-direct competition
excluding others from a given area or resource aggressive behavior/territoriality |
Interference Competition
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intense competition selection will favor those that engage in behaviors that reduce/avoid competition
subdividing niche-specializing with microhabitats reduction of competition due to shift in fundamental niche |
Resource Partitioning
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when ranges of two populations overlap
-differences between two species may vary between areas of overlap(sympatry) and non-overlap(allopatry) allopatric-morphological similarity sympatric-divergence in morphology, reduce competition |
Character Displacement
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the back and forth evolution of defense and offense between predator and prey that can often result in rapid evolutionary change in both species
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Coevolutionary Arms Race
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PREDATOR IS HUNTING FOR ITS DINNER: if it fails in an encounter with a prey it loses only a meal and the effect on predator fitness is relatively small
PREY IS RUNNING FOR ITS LIFE: if it fails in an encounter with a predator, it loses its life and the effect on prey fitness is very large |
Life Dinner Principle
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in an ecosystem, an organism that utilizes energy of the sun and inorganic molecules from the environment to synthesize organic molecules
(ex: green photosynthetic plants) |
Primary Producers
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animals that eat primary consumers; carnivores that eat herbivores.
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Secondary Consumers
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an animal that feeds only on secondary consumers; a carnivore at the topmost level in a food chain that feeds on other carnivores
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Tertiary Consumers
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the rate at which all the primary producers in a particular community turn solar energy into stored chemical energy via photosynthesis
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Gross Primary Productivity (GPP)
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the energy accumulated from (GPP)
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Gross Primary Production
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the rate at which energy is incorporated into the primary producers bodies through growth and reproduction
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Net Primary Productivity (NPP)
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amount of primary producer biomass available for consumption by heteroptrophs
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Net Primary Production
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a group of organisms united by obtaining their energy from the same part of the food web of a biological community
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Trophic level
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interactions of a single consumer with other species in its community causing a progression of indirect effects across successive trophic levels
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Trophic Cascade
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Dynamics of one species at a given trophic level influence the abundance of another species at one successive trophic level
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Direct effects of Trophic levels
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Dynamics of one species at a given trophic level influence the abundance of other species at multiple trophic levels
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Indirect effects of Trophic levels
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-indirect effects
-change at higher trophic level impacts lower trophic level -alternating change in trophic levels(increase then decrease in density) |
Top-Down Effects
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-indirect effects
-change at lower trophic levels impact higher trophic levels -consistent change(increase or decrease) through trophic levels |
Bottom-Up Effects
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