Chapter 5 Flashcards
What is Population Biology?
the science of modeling changes in species abundance
What are the factors that control population?
Morality
Reproductive rates
Resources
Competition
Disease
Accident
What are ways species get onto the islands?
Walking
Flying
Hitchhiking
rafting
Ballooning
Drifting in air
Swimming and floating
What are factors for population founders to exist on the island’s resources?
Habitat must be available and suitable
Mates present
Food present
Nursery habitat presents
(There are unique species that would have been remarkable, but did not have the right resources)
Predator?
Competitors?
Disease?
All individuals alive today are part of a continuum of success since the dawn of life!
What is the equation for N (Population size)?
N (population size) = Increase population size (birth + immigration) - decrease population size (death - emigration)
What are the changes of population for basic models of population growth under “closed” population (no immigration and emigration)?
Birth rate > death rate, N increases
Birth rate < death rate, N decreases
Birth rate = death rate, N stays the same
Many populations can be modeled by a ____________.
Sigmoid curve
What are the three phases of population growth?
Lag phase
- Slow (but positive_ growth at low N
- B > D
Exponential phase
- Population increases rapidly over short time steps as N gets larger
- B > D
Stationary Phase
- Population reaches the carrying capacity (K)
- B = D
What is carrying capacity?
Known as K
maximum number of individuals an environment can support
What is biotic potential?
The ability for a species to increase its population size if all offspring survive to reproduce in their parents’ turn
- Species that have high fecundity will have greater biotic potential than species with low fecundity
maximum reproductive rate of an organism, given unlimited resources and ideal environmental conditions
What is exponential growth rate?
a population can only grow at an exponential rate this fast if nothing limits its growth
What is fecundity?
high reproductive output
What is doubling time?
the time required for a population to double in number
- Larger populations will have generally have shorter doubling times than smaller population
Islands connected to a continent became populated by ___________________ that could fly, float, or hitchhike across the ocean barrier.
indigenous species
Species migration includes not only the travel to the island, but also…..
successful establishment of a population.
Population on islands are founded when…..
1+ individuals capable of reproducing establish successfully.
Population growth often approximates an ______________ curve that reaches a maximum at the carrying capacity of the environment.
S-shaped
Globally, human population growth has _____________ a little, but some regions still have very ________ growth rates.
slowed; high
The global population is likely to rise by another _____________ during the first half of the 21st century .
3 billion
Population can rarely be _________________, but the size must be estimated from statistically valid samples.
counted exactly
What is population?
All of the members of a species within a particular area
1st level of biological organization beyond the individual organism
In some cases, populations may undergo rapid ______________, leading to population collapse.
“boom-and-bust” growth
What is Demography?
is the statistical study of population
What are the different types of population growth graphs?
Rapid growth
- Juvenile section is the largest section (poor people = more babies)
Stable
- Graph stays consistent
Declining
- Fertile adults is a large chunk but the juvenile begins to decrease in numbers
If you can bring down your deathrate, why does the birthrate decline?
Education, modern technology, and better and more available resources.
How do we end poverty?
Empowerment of women
Women’s right affect fertility
Total fertility declines as women’s education increases
How do we measure a population?
- Census
- Transects/Quadrats/Plots
- Mark-recapture methods
- Many More!
What are communities?
All of the species populations in a habitat and their interactions
Examples include:
- Predators and prey relationship
- Football web
- Competitive
(Focus on these two topics)
- Symbiosis
- Successes
What is Symbiosis? What is Symbionts?
Symbiosis: “Living together”
Symbionts: Organisms in a symbiotic association
What are the outcomes for the symbiotic relationship between two factors?
Mutualism (+ +)
Parasitism (+ -)
Commensalism (+ NA)
For Guam:
How have the distribution changed over time?
What do you think are the factors responsible for those changes?
What are the implications for future population growth rates for Guam?
Developing country => developed country
Longer juvenile population (baby mamas)
Baby mamas did not have as much children
Family size decrease (slow growth rate)
Less abundant juvenile population
What is in the Trophic Pyramid?
Top Consumers
Secondary Consumer
Primary Consumers
Primary Producers
Rule of squares (x^2)
1
100
10,000
10,000,000
What is the Inverted Trophic Pyramid of the Warm Tropic Ocean?
Big fish
Reef fish
Crabs, shrimps, starfish
Seaweed and algae
What are the Primary Producers in the Ocean?
Found the base in 2 places
- Fleshy encrusting algae
4 x biomass of primary producers
40 x biomass of carnivores
Primary Producers = ⅓
- Corals
What is a Coral?
Coral is a predacious animal - not a plant!
Related to jelly fish and anemones
Coral polyps fee a night - daily plankton migration
What is the Symbiotic Relationship of Corals and Zooxanthellae
Corals (a predator)
- Heterotrophic (N+P)
- Give nutrients and CO2
- Receive Fixed C and O2
- Nutrients = nitrogen + phosphorus as waste products
Zooxanthellae (Symbiotic plant in the coral that helps feed it)
- Autotrophic (N+P)
- Receive nutrients and CO2
- Give Fixed C and O2; sugars
⅔ of the primary producers are made up of Zooxanthellae that lives in corals
How do Biological communities grow?
Succession
What is Succession?
How population or communities would grow over time.
Changes over time in the species present for a given place
What is Primary Succession?
Succession on a previously uncolonized substrate
- Fresh substrate is nutrient poor and undeveloped
- Initial colonists are pioneer species that grow quickly (e.g., vines) with low investment in hard structures (like wood or carbonate)
- Pioneer species may eventually modify the substrate (e.g., increasing nutrients and soil depth in terrestrial system) future colonists
- Over time competitively dominant species replace pioneer species, often in a predictable sequence
What is Secondary Succession?
Succession on previously colonized substrate
- Substrates (e.g., soil) may be suitable for colonization, Composition is included by the composition of the surrounding communities
- Pioneer species grow quickly on exposed surfaces but are eventually replaced by woodlier, more recent growth forms
How is Zonation different from succession?
Zonation - Changes in species composition along a transect/distance/space
- Characteristic changes
Succession - Changes in species competition in a given place (space that changes over-time)
