Unit 3: Biodiversity & Conservation Flashcards
natural selection
those more adapted thrive and reproduce while others don’t live long enough to have off spring
speciation
the formation of a new species when populations of a species become isolated and evolve differently
What physical barriers can cause speciation?
mountains ranges or ocean
What factors aside from physical barriers (ex: mountain ranges and ocean) isolate a species, leading to speciation?
their mating seasons are not synchronized or their flowers mature at different times
What do land bridges allow for?
allow species to invade new areas
How are land bridges temporarily formed?
the lowering of sea levels, ice age
What is an example of a land bridge that has formed between North and South America?
Central America (North and South America were separated for a long time)
plate tectonics
the study of the movement of the plates
What effect does continental drift have on biodiversity?
Biodiversity increases because the number of degree of separation of habitats increases, promoting speciation, and species arrive or evolve
What is a result of the creation of mountain ranges, etc. through plate tectonics?
new habitats/niches
r
biotic potential/how fast a species can reproduce
What are the three types of biodiversity?
species, genetic, habitat
keystone species
a species that contributes greatly to an ecosystem even though they may not dominate in numbers
indicator species
serves as an early warning that an ecosystem is declining
foundation species
plays a major role in shaping communities by creating land enhancing habitats in ways that benefit other species
What is an example of a foundation species?
elephants (push over/uproot trees which creates opportunities for growth of grasses which benefits grazing species)
What is an example of a keystone species?
birds (seed dispersal/pollination)
K
carrying capacity
What is species diversity based on?
species richness and species evenness
species richness
variety/number of species
species evenness
abundance/number of organisms within a species
genetic diversity
the range of genetic material present in a gene pool or population of a species
habitat diversity
the range of different habitats in a particular ecosystem/biome
Where would habitat diversity be high?
the tropics, tropical rainforests