Available at most book stores and through online bookdealers. Although not required, you will probably find this book useful, particularly before exams or if you plan more coursework in ecology or biology. Speciation may occur allopatrically or sympatrically. Allopatric-divergence occurs in different places due to barriers to dispersal, geographic separation, vicariant events, and founder events. Sympatric-speciation occurs in spatially contiguous populations.
Divergence occurs in the same place.
Occurs through disruptive selection or chromosomal changes. Lake Victoria in Africa is an example of sympatric fish speciation. As new species originate older ones may continue to exist or become extinct. The lineage of a species differs from the lineage of an individual. Successful speciation may occur because certain adaptations provide for increased success in differential reproduction, i.e., natural selection.