Chapter 16: Evolution on a Large Scale Flashcards
Macroevolution
large-scale changes in a population over very long periods of time
Speciation
the formation of new species due to evolutionary processes
Allopatiric- model of speciation
speciation model based on the geographic isolation of populations
Sympatric- model of speciation
a population develops into two or more reproductively isolated groups without prior geographic isolation
Biological species concept
Interbreed, have shared gene pool, each species reproductively isolated from every other species
Reproductive Barriers
isolating mechanisms that prevent successful reproduction from occurring
Prezygotic -reproductive barrier
before the formation of the zygote
Habitat isolation -prezygotic
two species occupy different habitats
Temporal isolation -prezygotic
two species can live in the same local but reproduce at different times of year
Behavioral isolation -prezygotic
a species using something like courtship patterns that allow females and males to recognize each other or chemical signals
Mechanical isolation -prezygotic
when animal genitalia or plant floral structures are incompatible
Gamate isolation -prezygotic
even if two species meet, they may not fuse to become a zygote
Postzygotic isolating mechanisms
occur afterhte formaiton of a zygote
Zygopte motality -postzygotic
the hybrid zygote may not be viable, so it dies
Hybrid sterility -postzygotic
the hybrid zygote may develop into a sterile adult
