Eccology Exam 3 Flashcards
Why study population?
To understand ecosystem and niche of species.
Environmental Resistance
Limited by available resources
K=
Carrying capacity
R selected
Intrinsic rate of increase, small offspring, no parental care. Often annual.
K selected
Slow growth, long-lived. High competition
Carrying capacity
Can not be predicted, for some species can differ location.
Population Regulation
Density independent controls
Destruction of habitat
Unseasonal temperatures
Density Independent controls
Limiting factors affect the population irrespective of the population density.
Density-dependent population controls
Limiting factors become more influential
population density increase
force changes as density changes
conspecific
Individuals with other individuals of the same species
Ecological pressures for group living
Predation pressure
Food acquisition
Territory defense
Thermoregulation
Dilution effect
more people less risk of individual getting hurt
Center VS Edge
Lower risk of predation
Selfish heard
Moving to an area for prevention of predation.
Increased Vigilance
Individuals looking around observing surroundings for predators.
Cost of group living increased
Competition for resources
conspicuousness
Disease and parasitism
Cannaibalism and cuckoldry
Cuckoldry
Individual stealing a mate.
Altruism
Altruist increases the reproductive success of a recipient at the cost of it’s own direct reproduction.
Kin selection
A form of natural selection where an individual will sacrifice their life to help related organisms.
Mutualism
Individual derives benefits from the interactions regardless of relatedness
Manipulation
One individual cooperates and may be giving altruistic behavior because it is being tricked.
Reciprocity
Model of how altruistic behavior will evolve with
immediate costs but the recipient of the behavior
repays the altruist later
(A helps B today, B helps A tomorrow)
traits that influence fitness to influence survival or reproduction
size
growth and development
clutch number
reproductive allocation
Life History traits
growth trajectory
* age and size at first
reproduction
* schedule of reproduction
(iteroparity vs.
semelparity)
* number and size of
offspring to have
* how long to live
Increase human lifespan?
Delay reproduction
why is evolution in nature complex
-organisms interact with organisms of their type, other types,
and their physical environment
– Interactors/interactions may change over time
fitness benefits of being large
-competitavly superior
-Better predators
-Maintain constant body function
-More offspring.
Fitness cost of being large
-More energy for growth
-More worthy prey items
-More energy for maintenance
-More energy for offspring
Fitness benefits of rapid growth
-reproduce sooner
-short generation time
-High rate of increase in population
Fitness cost of rapid growth
-Requires much energy
-Vulnerable in hard Times
What are trade-offs among components
Relationships among life history characterization where the benefits from one leads to cost in another.
(usually because of limited resources)
What links life history traits together?
Problems with investigating trade-offs
(reproduction vs growth)
Trade-Offs to influence life history
account for the variation in life history strategies among species.
Inference
only those phenotypes best able to
grow, survive, gather resources, and reproduce will leave offspring; other phenotypes die out
(Natural selection)
Inference
the makeup of the population will change over generations, increasing the representation of
the best phenotypes and genotypes
(Evolution)
