AND ANSWERS SURE A+
✔✔Define speciation - ✔✔the formation of new and distinct species in the course of
evolution
✔✔How can species become evolutionary independent? - ✔✔little gene flow between
different species
✔✔How can you tell if they are two species? - ✔✔-they can mate
-the don't look like each other
✔✔Define biological species concept - ✔✔one or more populations whose members
interbreed under natural conditions & produce fertile offspring
✔✔Why might individuals within a species not mate? - ✔✔-asexual
-geographic
✔✔Define morphological species concept - ✔✔use visible morphology (do they look
different?)
✔✔Define ecological species concept - ✔✔-species can be characterizes by its
ecological niche
,-two species cannot occupy the same niche in the same location due to competition
-can apply to telling some bacterial species apart
✔✔What are the two steps of speciation? - ✔✔-initial identical populations must have
restricted gene flow so they can diverge
-reproductive isolating mechanisms must evolve to maintain these differences
✔✔Define macroevolution - ✔✔evolutionary change above the species level, including
the origin of a new group of organisms or a shift in the broad pattern of evolutionary
changes over time
✔✔How do we identify a species? - ✔✔groups of actually or potentially interbreeding
populations that are reproductivley isolated from other such groups
✔✔Define reproductive isolation - ✔✔cannot produce viable offspring
✔✔Define viable - ✔✔offspring can reproduce
✔✔Define speciation - ✔✔splitting event that creates two or more distinct species from
a single ancestral group
✔✔What are the three stages of specification? - ✔✔1. population separation
2. divergence
3. productive isolation preventing gene flow
✔✔Define population separation - ✔✔isolation of gene pool
✔✔Define divergence - ✔✔changes in gene pool (1 or both)
✔✔What are the two types of separation of populations? - ✔✔-allopatric model
-sympatric model
✔✔Define allopatric model - ✔✔separation due to geographic isolation
✔✔Define sympatric model - ✔✔separation due to competition or polylodisism in
population
✔✔What are the mechanisms of allopatric separation? - ✔✔-dispersal and colonization
-vicariance
✔✔Define dispersal and colonization - ✔✔-start with one continuous population
-goes to an isolated area (island)
-finishes with one population isolated from the other
, ✔✔Define vicariance - ✔✔-start with one continuous population
-landscape is changed
-two populations are isolated from one another
✔✔When does peripatric speciation occur? - ✔✔when one of the isolated populations
have very few individuals
✔✔What causes divergence of populations in sympatric speciation? - ✔✔-disruptive
selection
-polyplodism
✔✔Define adaptive radiation - ✔✔the rapid diversification of a group of organisms into
forms filling different ecological niches via sympatry
✔✔Define niches - ✔✔role you fill in given environment
✔✔What drives adaptive radiation? - ✔✔-opportunity
-morphological innovations
-sex
✔✔How would you know if two species are productively isolated? - ✔✔- unsuccessfully
interbreed
-produce viable hybrids that are selected against
✔✔What are the types of prezygotic barriers? - ✔✔-habit isolation
-temporal isolation
-behavioral isolation
-mechanical isolation
-gametic isolation
✔✔Define habit isolation - ✔✔different species breed in different habitats
✔✔Define temporal isolation - ✔✔different species breed at different times
✔✔Define behavioral isolation - ✔✔unique behavioral patters and rituals isolate species
✔✔Define mechanical isolation - ✔✔anatomical incompatibility preventing mating or
pollen transfer
✔✔Define gametic isolation - ✔✔sperm and ova are chemically incompatible and will
not fuse to form a zygote
✔✔What are the postzygotic barriers? - ✔✔-reduced hybrid viability
-hybrid sterility