BIO Finals Flashcards
Group of potentially interbreeding individuals of a single species inhabiting a specific area
Population
How are attributes of populations determined?
They are determined by interactions between the physiological ecology of a species and the biotic/abiotic conditions that a population encounters
What do ecological filters determine?
Ecological filters determine where different species may become established and where they may thrive
Can be absolute density or ecological density
Population density
The number of individuals of a population per unit area
Absolute density
Incorporates the concept of the niche; the number of individuals per unit of suitable habitat
Ecological density
What are some additional characteristics of populations?
Age distributions, sex ratios, birth and death rates, immigration and emigration rates, rates of growth
An abstract concept that represents multidimensional conditions necessary for a species to persist
Niche
Where can macropods (kangaroos, wallabies) be located in Australia?
They can be found nearly in every part of Australia but no single species ranges across the entire continent
What is a determining factor of a species’ geographic distribution?
the supply of biotic/abiotic conditions and niche requirements
Where are the eastern gray kangaroo confined?
to the eastern third of the continent (temperate forests in the southeast, tropical ones in the north, mountains in the center); areas with little seasonal variation in precipitation or dominance by summer precipitation
Where are the western gray kangaroo confined?
mainly in the southern and western regions of Australia (temperate woodland and shrubland biome); predominance of winter rainfall
Where are the red kangaroo confined?
the arid and semiarid interior of Australia with biomes that include the savanna and desert (hottest and driest areas)
Which area of Australia is not occupied by kangaroos?
the northernmost region of Australia (where tropical forests are common)
What does climate also affect?
suitable food, habitat, incidence of parasites, pathogens and competitors that can further restrict the realized niche of species
The seasonal movement of individuals from one location to another
Migration
A permanent exodus from one population into another
Dispersal
Those in the process of increasing their geographic range
Expanding populations
Where did honeybees evolve?
Africa and Europe, where native range extends from tropical to cold, temperate environments
How were honeybees improved in terms of adaptability?
Queens of the African subspecies were imported and were mated with European honeybees, producing Africanized bees
How do Africanized honeybees differ from European bees?
They differ in natural selection (Africanized bees are more aggressive); A-bees also produce swarms to form new colonies at a much higher rate than European rates do
What caused the rapid expansion of Africanized bees through South and North America?
high rates of colony formation and dispersal
Where has the honeybees stopped spreading? how many colonies are there in South America?
they stopped at about 34 degrees S latitude; an estimated number of wild colonies is about 50-100 million
Why don’t Africanized bees live in North America?
Cold winter temperatures fall outside of the tolerance for these bees; it does not overlap with the niche requirements of this species
