Chapter 52 Flashcards
population
A group of organisms of one species that interbreed and live in the same place at the same time
quadrats
It marks off an exact area so that the plants in that area can be identified and counted. About quadrats: quadrats should be placed randomly so that a representative sample is taken.
evolutionary ecology
lies at the intersection of ecology and evolutionary biology. It approaches the study of ecology in a way that explicitly considers the evolutionary histories of species and the interactions between them.
intrinsic rate of increase
The rate at which a population increases in size if there are no density-dependent forces regulating the population
mark-recapture study
a method commonly used in ecology to estimate an animal population’s size. A portion of the population is captured, marked, and released. Later, another portion is captured and the number of marked individuals within the sample is counted.
immigration
Migration into a place
exponential growth
Growth of a system in which the amount being added to the system is proportional to the amount already present: the bigger the system is, the greater the increase.
population cycles
a phenomenon where populations rise and fall over a predictable period of time. There are some species where population numbers have reasonably predictable patterns of change although the full reasons for population cycles is one of the major unsolved ecological problems.
emigration
migration seen as an the exit of individuals from one region
density-independent
Any factor limiting the size of a population whose effect is not dependent on the number of individuals in the population.
age structure
This characteristic is as simple as it sounds: it’s a summary of the number of individuals of each age in the population. Age structure is useful in understanding and predicting population growth.
demography
the science of populations.
population density
a measure of the number of organisms that make up a population in a defined area.
age pyramid
a graphical illustration that shows the distribution of various age groups in a population (typically that of a country or region of the world), which forms the shape of a pyramid when the population is growing.
generation
All of the offspring that are at the same stage of descent from a common ancestor: Mother and daughters represent two generations.
density-dependent
Any factor limiting the size of a population whose effect is dependent on the number of individuals in the population.
replacement rate
The rate at which new offspring are born compared to the death rate.
life table
a table which shows, for each age, what the probability is that a person of that age will die before his or her next birthday (“probability of death”).
carrying capacity
the maximum population size of the species that the environment can sustain indefinitely, given the food, habitat, water, and other necessities available in the environment.
zero population growth
A condition in which a population neither grows nor declines, because the number of births in a year equals the number of deaths.
per capita rate of increase
A rate of increase which is proportional to the number of individuals in a population.
cohort
a group of individuals that are the same age and can be followed through time
logistic growth equation
expressed as change in population/change in time=growth rate(initial population)(carrying capacity -initial population/carrying capacity)
logistic population growth
the density-dependent decrease in growth rate as a population size approaches carrying capacity
fecundity
the average number of female offspring produced by a single female in the course of her lifetime
finite rate of increase
the rate of increase of a population over a given period of time. calculated as the end population size over the start population size
age-specific fecundity
the average number of female offspring produced by a female in a certain age class
population viability analysis
a model that estimates the likelihood that a population will avoid extinction for a given time period
density dependent factor
in population ecology referring to any characteristic that varies depending on population density
age class
all the individuals of a certain age in a population
fitness trade-off
in evolutionary biology, an inescapable compromise between two traits that cannot be optimized simultaneously
life history
the sequence off events in an individuals life from birth to reproduction to death, including how an individual allocates resources to growth, reproduction, and activities or structures related to survival
population dynamics
changes in the size and other characteristics of populations through time
net reproductive rate
the growth rate of a population per generation; equivalent to the average number of female offspring that each female produces over her lifetime
metapopulation
a population made up of many small, physically isolated populations
