Ecology Flashcards
Population
Individuals of one species simultaneously occupying the same general area, utilising the the same resources and influence by similar environmental factors
Population ecology
The study of changes in population size and composition and of the factors that cause these changes
Density
The number of individuals per unit area or volume
Dispersion
The pattern of spacing among individuals
Mark and recapture formula
No. of recaptures/ no. total 2nd capture = no. total 1st capture/ N
Life table
An age specific summary of the survival pattern of a population. It usually follows the fate of one cohort- age group
Survivorship curve
Graphical representation of the survival pattern of a population
Exponential growth formula
dN/dT =1.0N
Logistic growth formula
dN/dT =1.0N (K-N/K)
Carrying capacity
The maximum population size the environment can support
Competitive exclusion principle
When populations of two similar species compete for the same limited resources, one pop. will use the resources more efficiently and have a reproductive advantage that will eventually lead to the elimination of the other population
Ecological niche
The sum total of a species’ use of biotic and abiotic resources in the environment
Fundamental niche
The potential niche that an animal could occupy
Realised niche
The actual niche that an animal occupies ( often reduced due to competition )
Resource partitioning
The division of environmental resources by co-existing species such that the niche of each species differs by one or more significant factors
Character displacement
The tendency for characteristics to be more divergent in sympathetic populations of two species than in allopatric populations of the same two species
Sympatric populations
Populations that exist in the same geographic area and this regularly encounter one another
Sympatric species
An initially interbreeding population that splits into two or more distinct species sharing sharing a common range exemplifies sympatric speciation
Allopatric populations
Related organism that are unable to interbreed because of geographic separation
Allopatric speciation
The development of new species as a result of geographic separation of populations
Batesian mimicry
When a harmless species imitates a harmful species e.g hawkmoth larvae
Mullerian mimicry
Two or more unpalatable species resemble each other e.g cuckoo bee and yellow jacket have similar colouring that predators learn to avoid
