Species Lecture Flashcards
What is allopatric speciation?
speciation as a result of geographic isolation within a species
species are not together
What drives allopatric speciation?
it could be ecological reasons (food, habitat)
it could be random
What is the key component to biological species concept?
sympatry
What is sympatry?
when two now different species come back together and CANNOT interbreed
What is the biological species concept?
“species are a group of freely interbreeding natural populations that are reproductively isolated from other groups”
What is assortative mating?
like breeds with like.
ex: bird with red feathers are more inclined to mating with other red feathered birds, keep the line pure.
What is sexual selection?
some females might prefer certain phenotypes over others
What are examples of pre-zygotic mechanisms?
assortative mating
sexual selection
behavior
what is an incipient species?
a species that is in the process of splitting apart
How do species maintain reproductive isolation while in sympatry?
they have either pre-zygotic preventative mechanisms or post-zygotic preventative mechanisms
what does pre-zygotic mechanisms result in?
no hybrids produced
what does post-zygotic mechanisms result in?
hybrid inferiority
Explain what happened with Darwin’s finches.
1) Species A gets blown off its migratory path and lands on island A.
2) Evolution happens
3) very rare and random occurrence causes some of these birds to become isolated on another island. (ALLOPATRY)
4) Evolution happens
5) steps 3 and 4 repeat a few times until eventually some of these birds end up back on island A and undergo Sympatry.
What is the main reason for allopatric speciation?
climate change
What caused allopatric speciation in yellow rumped warblers?
glacier came down and split the population up into two populations that diverged. Autobon’s warbler went to the west coast and Myrtle went to the east coast, but both are yellow-rumped.They were not separated long enough for reproductive isolating mechanisms to evolve.
