Chpt 24: (12) Species and Speciation Flashcards
Poor/Reduced Hybrid viability
1 of 2 types of POSTzygotic reproductive isolation
When hybrid offspring don’t develop normally and die
Gradual model (of speciation)
rate of speciation where species diverge steadily over time
exp. from class butterflies from oranges to pink through a series of shades of orange, then orange pink, then pink
2 types of reproductive isolation
prezygotic
postzygotic
temporal isolation
1 of 3 types of prezygotic reproductive isolation
when males and females come into heat/breed at different times
exp. from class was the plant with male and female blooming at different times
exp. from BOOK bishop pines and monterey pines release their pollen at different times of the year
Competitive exclusion (principle)
the idea that two species occupying the EXACT same niche cannot coexist (because one will outcompete the other)
exp. from class: Hawaiian honey crisper birds
Postzygotic reproductive isolation
1 of 2 types of reproductive isolation
prevents hybridoffspring from surviving/mating
Parapatric speciation
1 of 3 modes of speciation
when a geographically CONTINUOUS population is spread over extremely vast distances (usually, with very different selection pressures) AND each species can breed with its neighbors, but not with the species located on the other side of the divide EXCEPT at the point (in the ‘ring’) where the populations rejoin
exp. from class was the Canadian and Southern Californian spread of little colorful lizards
speciation
when populations achieve reproductive isolation
Dispersal
1 of 2 modes of allopatric speciation
when population is split up (because some members move away) and the population is NO LONGER CONTINUOUS
exp. from class fruit flies that moved to a new island in Hawaii
Vicariance
1 of 2 modes of allopatric speciation
population split up by geographic barrier
exp. from class is chipmunks growing on opposite sides of a canyon
biological species concept
the idea that species can be separated by whether or not they can produce fertile offspring
exp. from class: 2 types of elephants
Allopatric speciation
1 of 3 modes of speciation
gene flow prevented by geographic isolation
Hybrid sterility
1 of 2 types of POSTzygotic reproductive isolation
When hybrid offspring survive to mating age, but they are sterile
exp. from class: fertile horses and fertile donkeys make sterile mules
Resource partitioning
when similar species can coexist in an area if they use different sets of similar resources or the same resource at different times
exp. from class: Hawaiian honey crisper birds
niche
the specific biotic and abiotic resources used by a species
Prezygotic reproductive isolation
1 of 2 types of reproductive isolation
prevents mating OR prevents fertilization after mating
Habitat (barrier)
1 of 5 types of prezygotic reproductive isolation
when populations don’t interbreed bc they breed in different habitats
biotic
r/t or resulting from living organisms (especially in their ecological relationships)
Punctuated equilibrium (model)
describes a rate for speciation where rapid bursts of speciations followed by little change
exp. from class butterflies change from orange to pink in one felt swoop
behavioral isolation
1 of 5 types of prezygotic reproductive isolation
when populations don’t interred bc they have different courting behaviors
exp. from class: overly elaborate courting of snails
ring population
part of parapatric speciations
continuous population over a large geographic area that can interbreed except where they populations rejoin
exp. from class was the Canadian and Southern Californian spread of little colorful lizards
mechanical isolation
1 of 5 types of prezygotic reproductive isolation
when mating fails bc reproductive structures are incompatible
exp. from book: great dane vs chihuahua
gametic barrier/incompatibility
1 of 5 types of prezygotic reproductive isolation
when matings fail bc egg and sperm are not compatible
Dr. C calls it gametic isolation
genetic species concept
the idea that species can be separated by genetic makeup OR by shared evolutionary history
exp. from class: 2 types of elephants