– Gene flow refers to the transfer of alleles among populations. As long as populations are exchanging alleles, speciation is unlikely.
– If two individuals cannot interbreed and produce viable, fertile offspring, they are members of different species.
– Allopatric speciation occurs when a population of organisms is geographically separated long enough for significant changes to occur. After a period of time, the populations may no longer be able to interbreed.
– In temporal isolation, two species that breed during different times of the day cannot mix their gametes.
– It is due to a radical change in the genome.
– A hybrid zone allows researchers to see what happens when closely related species come together. Reproductive barriers may be strengthened or weakened, depending on environmental and genetic factors.
Fusion refers to the weakening of reproductive barriers, allowing the two populations to fuse and remain (or become) one species.
– This is the definition of punctuated equilibrium.
– Autopolyploidy has been shown to produce nearly instantaneous speciation in plants.