Briefly describe speciation. Differentiate between allopatric and sympatric spec

When mutations occur in one population that are not passed to another population, or if natural selection favors genes in one population and not the other, speciation can occur if gene flow becomes restricted permanently between the two populations (i.e., they can no longer mate and produce fertile offspring). If a physical boundary such as a stream divides the two populations, restricting gene flow between them, and a speciation event occurs, this is termed allopatric speciation. If it occurs in one location without a physical barrier, this is sympatric speciation.