Ecology and Evolution chap 12

define population

a group of individuals of the SAME species that live in the same AREA (interbreeding)

what is the fundamental unit of evolution

population

what is spatial structure

the pattern of density and spacing of individuals in a population

what is a fundamental niche

a range of abiotic conditions (humidity, temperature, salinity) under which a species can persist

realized niche

the range of abiotic and biotic conditions under which a species does persist

what is geographic range

a measure of the total area covered by a population (temp and drought define the range of sugar maple)

what may prevent a population from persisting in an area

predators, competitors, and pathogens

a study of a plant species investigated how temperature and soil acidity limits where a species can occur, but did not look at the potential impacts of competition or mutualisms. What would the results of this study reflect

a. the plants realized niche

b. the plants biotic limitation

c. the plants ecological envelope

d. the plants fundamental niche

the plants fundamental niche

what creates geographic ranges that are composed of small patches of suitable environment

smale-scale variation in the environment

what does endemic mean when talking about geographic range

species that live in a single, often isolated, location

what does cosmopolitan mean when talking about geographic range

species wit very large geographic ranges that can span several continents

what does abundance mean when talking about geographic range

the total number of individuals in a population tat exist within a defined area (total number of lizards on a mountain)

what does density mean

In a population, the number of individuals per unit area of volume; calculated by dividing abundance by area

if population density is ___ than what the habitat can support, some individuals must leave or the populations will experience lower growth and survival

greater

the largest density of individuals typically occurs

near the center of the populations geographic range

what happens near the ends of the populations geographic range

conditions become less ideal and population densities decrease

what is dispersion

the spacing of individuals with respect to one another within the geographic range of a population

what is clustered dispersion

when individuals are aggregated in discrete groups (social groups or clustering around resources)

evenly spaced dispersion

when each individual maintains a uniform distance between itself and its neighbors

what is random dispersion

when the position of each individual is independent of other

which species provides an example of an event spaced dispersion pattern

a. lizards defending similarly sized territories in rocky glade

b. fish swimming schools for predator protection

c. zebra collection around a watering hole to drink

d. dandelions in a field are positioned independently of each other; some are close together, others are far apart

lizards defending similarly sized territories in rocky glade

what is dispersal

the movement of individuals from one area to another

what is the mechanism by which individuals can move between suitable habitats

dispersal

what allows species to colonize areas outside their geographic ranges

dispersal

what can be a way to avoid areas of high competition or high predation risk

dispersal