Population Dynamics Flashcards
Natural selection favors traits that increase…
Fitness
There are always trade-offs between traits that affect…
Fitness
Life history
Traits that affect an organism’s schedule of reproduction and survival
Examples of life history
Frequency of reproduction
Number of offspring
Investment in parental care
Reproductive strategy
Life history traits are evolutionary outcomes reflected…
In an organism’s development, physiology and behavior
Components of diversity of life histories
When replication begins (age at first reproduction or age at maturity)
How often the organisms reproduces
How many offspring are produced
When reproduction begins:
Organisms differ in age of first reproduction
Semelparity
One shot pattern of big-bang reproduction; single reproductive event
Ex. Coho salmon
Iteroparity
Repeated reproductive events throughout organism’s life Ex. Loggerhead sea turtles
Trade offs exist because
Organisms do not have access to unlimited resources
Examples of trade offs
Resources specialization
Energy expenditure
Predator vs. prey dynamics
Reproductive strategy
Selective pressures in a survivorship curve
Size of offspring and number of offspring
The survival of offspring and parental care
Predation and number of offspring
Offspring size and dispersal ability
Population growth can be affected by…
Density independent and density dependent factors
Density independent
Birth rate or death rate does not change with population size
Controlled abiotic variables
Flood
Fire
Spraying with pesticides
Change in temperature
Habitat destruction
Drought
