Exam 3 Flashcards
population
group of individuals of the same species that live in the same area at the same time
population ecology
study of how and why the number of individuals in a population changes over time
immigration
when individuals enter a population by moving from another population
emigration
when individuals leave a population to join another population
demography
the study of factors that determine the size and structure of populations through time
generation
avg. time between a mother’s first offspring and her daughter’s first offspring
life table
summarizes the probability that an individual will survive and reproduce in any given time interval over the course of its lifetime
survivorship
the proportion of offspring produced that survive, on avg., to a particular age
cohort
group of the same age that can be followed through time
survivorship curve
logarithm of the number of survivors versus age
fecundity
the number of female offspring produces by each female in a population
age-specific fecundity
the avg. number of female offspring produced by a female in age class x
age class
a group of individuals of a specific age
fitness trade-offs
a compromise between two traits that cannot be optimized simultaneously
life history
describes how an individual allocates resources to growth, reproduction, and activities or structures that are related to survival
intrinsic rate of increase (r max)
when conditions are optimal for a particular species-high birthrates & low deathrates- then r reaches a maximal value
Exponential population growth
occurs when r does not change over time
density independent
refers to any characteristic that varies depending on population density
density dependent
any characteristic that does not vary with population density
population density
the number of individuals per unit area
carrying capacity (K)
the maximum number of individuals in a population that can be supported in a particular habitat over a sustained period of time
logistic population growth
changes in growth rate that occurs as a function of population size; logistic growth is density dependent
population dynamics
changes in populations through time
metapopulation
a population of populations
age structure
the proportion of individuals that are at each possible age
replacement rate
avg. fertility required for each woman to produce exactly enough offspring to replace herself and her offspring’s father
zero population growth (ZPG)
when the replacement fertility rate is sustained for a generation, r=0
behavior
the response to a stimulus
proximate causation
explains how actions occur in terms of the neurological, hormonal, and skeletal-muscular mechanisms involved
ultimate causation
explains why actions occur based on an animal’s evolutionary consequences and history
fixed action patterns (FAPS)
highly stereotyped behavior pattern that occurs in a certain way in a certain species; a form of innate behavior
innate behavior
behavior that is inherited genetically, does not have to be learned, and is typical of a species
cost-benefit analysis
decisions or analyses that weigh the fitness costs and benefits of a particular action
foraging
when animals seek food
optimal foraging
claim that animals maximize their feeding efficiency
ecology
the study of how organisms interact with their environment
community
consists of the species that interact with each other within a particular area
ecosystem
consists of all the organisms in a particular region along with nonliving components.
abiotic
“not-living” physical components that include air, water, and soil
conservation biology
effort to study, preserve, and restore threatened populations, communities, and ecosystems
biotic
“living” components that are members of the same or different species
turnovers
(in lake ecology) the complete mixing of upper and lower layers of water that occurs each spring and fall in temperate-zone lakes
thermocline
a gradient (cline) in environmental temperature across a large geographic area
